DE102019128669A1 - Pump unit, storage device equipped therewith and method for operating the storage device - Google Patents

Abstract

In order to make the two pump units (1), which are present in an emptying device for a storage container (101), alternately conveying on the one hand as inexpensive as possible and on the other hand with little wear and tear, both pump units (1) are equipped with a feed pump (1.1) in Equipped in the form of a diaphragm pump which is driven by a working cylinder unit (1.2); which is operated pneumatically in particular. Regardless of the type of drive of the feed pump (1.1), the axial position of the drive plunger (9) for the membrane (4) or the membrane (4) is constantly detected and the pump unit (1) is detected via this controlled.

Description

field of use

The invention relates to a pump unit for transporting liquid and, above all, viscous substances such as adhesives and resins, as well as a storage device which comprises a storage container for such materials, from which these materials are pumped to a downstream consumer by means of such a pump have to.

Technical background

Pasty materials in particular, e.g. casting compounds to encapsulate electronic circuits in a moisture-proof manner or adhesives to connect components tightly to one another, are often applied to the relevant components in the industry by means of appropriate, automated application processes using automatic dispensing machines, and must accordingly be constantly applied to the relevant components Material are supplied.

For this purpose, such a consumer is connected via lines to a storage device in which the corresponding material is located in a mostly pot-shaped storage container. In the line, which leads from a mostly deep removal opening of this storage container to the consumer, a pump unit is arranged, which effects the transport of this viscous material.

One problem is that these materials often contain abrasive solids in finely divided form, which is why certain pump designs, such as continuously operating screw pumps, cannot be considered.

Instead, piston pumps are often used which, even with abrasive material to be conveyed, wear less quickly and can also be manufactured more cost-effectively, but do not offer a continuous flow rate.

For this reason, two non-continuously delivering feed pumps, especially in the form of piston pumps, are operated in parallel, which are usually connected to the same storage container via separate connections and which are controlled in such a way that one piston pump just completes a working stroke, i.e. material in Ejects towards the consumer, while the other piston pump is currently completing a return stroke, i.e. its pump chamber is currently being filled with new material from the storage container.

Nevertheless, depending on the material to be conveyed, piston pumps also wear out during such use and have to be replaced from time to time, which on the one hand results in system downtimes and, of course, on the other hand, the costs for repair and assembly of the pump.

• Denn dieser Materialdruck, der vorliegt, wenn der Verbraucher kein Material entnimmt, also bei quasi geschlossener Auslassöffnung, kann einbrechen,
• wenn der Verbraucher Material aus der Pump-Einheit entnimmt, vor allem wenn dies relativ schnell geschieht. Der bei inaktivem Verbraucher dort anliegende Versorgungsdruck soll dabei jedoch nicht bis auf null absinken,
• weshalb - insbesondere abhängig vom Verbraucher - der Materialdruck an der Auslassöffnung bei inaktivem Verbraucher ein vorgegebener Solldruck pSoll sein soll.

However, a very precise volume to be maintained with each pump stroke is not necessarily a prerequisite for transport to the container, because there only has to be sufficient, preferably constant, pressure in the supply line to the consumer and thus in the outlet opening of the feed pump so that the consumer is always sufficient is supplied with material:

• Because this material pressure, which is present when the consumer does not remove any material, i.e. with the outlet opening virtually closed, can collapse,
• when the consumer removes material from the pumping unit, especially if this happens relatively quickly. However, the supply pressure present there when the consumer is inactive should not drop to zero,
• which is why - in particular depending on the consumer - the material pressure at the outlet opening should be a predetermined setpoint pressure pset when the consumer is inactive.

As soon as this removal has ended, the material pressure at the outlet opening of the pump unit, in particular the feed pump, and thus the supply pressure of the consumer, will rise again.

• - ein zusätzliches Rührwerk aufweisen, um das Sedimentieren schwererer Inhaltsstoffe zu verhindern, und/oder
• - eine Heizung aufweisen, um das viskose Material durch Temperaturerhöhung dünnflüssiger zu machen, und/oder
• - vor allem eine Entgasungseinheit aufweisen, um eventuell in dem Material noch vorhandene Lufteinschlüsse zu beseitigen, bevor das Material zum Verbraucher gepumpt wird.

Since it is often sensitive to their handling and storage materials, such storage containers

• - have an additional agitator to prevent the sedimentation of heavier ingredients, and / or
• - Have a heater in order to make the viscous material thinner by increasing the temperature, and / or
• - Above all, have a degassing unit in order to remove any air inclusions that may still be present in the material before the material is pumped to the consumer.

Presentation of the invention

Technical task

It is therefore the object of the invention to provide a pump unit - especially for the bearing device described - which is simple and inexpensive to manufacture, is subject to the least possible wear, a constant delivery pressure with a low structural level Effort enables, can also cope with materials with abrasive ingredients and which can also be exchanged quickly and easily if necessary.

Furthermore, it is the object of the invention to provide a method for operating such a pump unit which enables a defined, constant pressure at the outlet opening of the pump unit with little effort.

Solution of the task

This object is achieved by the features of claims 1, 15 and 19. Advantageous embodiments emerge from the subclaims.

Like every pump unit, a generic pump unit for pasty material also comprises a feed pump, which has a pump element that can be moved relative to the feed pump housing, and a feed pump drive for this feed pump.

According to the invention, the wear of the conveyor pump due to the material to be conveyed is reduced in that the pump element comprises at least one elastic element, preferably the elastic element itself is the pump element.

The elastic element is arranged in such a way that it is only in contact with the material to be conveyed on one side during pumping operation, and thus divides the space inside the feed pump housing into a conveying space in which the material to be conveyed is located, and a drive space through which the feed pump drive extends and in which there is no material to be conveyed.

Since the material to be conveyed cannot get between the elastic element on the one hand and other elements moving along the surface of the elastic element on the other hand, only little wear will occur, in particular caused by the abrasive properties of the material.

Such a pump unit preferably also comprises a controller, as a rule an electronic controller, which controls at least all movable components of the pump unit.

• Zum einen eine Faltenbalg-Pumpe, bei der ein Pump-Kolben in einem Pumpen-Gehäuse axial beweglich ist, jedoch liegt der Pump-Kolben mit seinem Außenumfang nicht dicht - sei es über Dichtungen oder Kolbenringe - an der Zylinderwandung an und verschiebt sich entlang dieser, sondern endet radial im Abstand zu der Innenumfangswand des Zylinders, wobei ein hülsenförmiger, elastischer Balg, meist ein Faltenbalg, mit seiner einen ringförmigen Endkante am Außenumfang des Pumpkolben dicht befestigt ist und mit seiner anderen ringförmigen Endkante am Pumpen-Gehäuse.

There are different types of pumps that include an elastic element as part of the pump element:

• On the one hand, a bellows pump in which a pump piston is axially movable in a pump housing, but the pump piston does not lie tightly against the cylinder wall with its outer circumference - be it via seals or piston rings - and moves along it , but ends radially at a distance from the inner circumferential wall of the cylinder, with a sleeve-shaped, elastic bellows, usually a bellows, with its one annular end edge tightly attached to the outer circumference of the pump piston and with its other annular end edge on the pump housing.

Another design is a so-called diaphragm pump, in which an elastic, approximately plate-shaped diaphragm divides the interior space in the pump housing - usually formed by two bell-shaped or cup-shaped housing parts that are tightly fastened with the open sides - the interior space in the pump housing into a pumping chamber and a working space divided, and is attached at its outer edge circumferentially tightly opposite the pump housing, for example, is tightly attached between the two screwed housing halves pressed against one another.

By moving the membrane transversely to its main plane, the conveying space is alternately enlarged and reduced, so that the material contained therein is pressed out through an outlet opening by means of corresponding inlet and outlet valves by means of the membrane from the conveying space filled with the material at maximum volume when its volume is reduced and is conveyed to the consumer and is filled with material when increasing its volume through the inlet opening.

The construction as a diaphragm pump, which is in the foreground of the present invention, is very simple and inexpensive to manufacture, since the individual components for this are inexpensive to manufacture due to only a few and also flat fitting surfaces, in contrast to a piston pump.

While the inlet valve is preferably an active, i.e. drivable and in particular controllably drivable, valve which, however, preferably only needs to be movable back and forth between the fully open and fully closed position, the outlet valve can be a simple, passive, i.e. not driven by a valve drive Be an outlet valve, for example in the form of a check valve. It will only be an active valve that can be driven in a controlled manner in special cases.

The outlet valve prevents material already in the outlet line from getting back into the delivery chamber of the diaphragm pump during the filling stroke, in which material through the inlet opening, in particular from the one to be emptied, by increasing its volume Reservoir, should arrive and this should be filled.

The non-return valve can be arranged with the larger side of its passage facing upwards and only assume the closed position by the weight of the valve element, usually a ball, and / or additionally be biased into the closed position by means of the force of a spring the effort for the manufacture of the required valves, especially the exhaust valve, is very low.

If, however, two pumps that do not deliver continuously, such as two diaphragm pumps, are operated alternately in parallel in order to achieve a flow to the consumer that is as constant as possible, the outlet valves are preferably controlled valves in order to be able to precisely control the open and closed intervals of the two outlet valves with respect to one another.

• Eine erste Möglichkeit besteht darin, den Antriebsraum der Förderpumpe abwechselnd direkt mit Unterdruck oder Überdruck eines Antriebsmediums, beispielsweise Luft, zu beaufschlagen.

Such a pump can be driven in different ways:

• A first possibility is to alternately apply negative pressure or positive pressure of a drive medium, for example air, directly to the drive space of the feed pump.

For this, however, a high pressure of the drive medium is required, and it is difficult to achieve reproducible delivery strokes.

The preferred second option is the feed pump, in the case of the diaphragm pump design the diaphragm of the pump, via a drive tappet whose front end is in operative connection with the side of the diaphragm facing away from the material to be conveyed, i.e. usually in the drive chamber, in particular is attached to this, driven transversely to its main plane. The rear end of the drive tappet, on the other hand, is in operative connection with the pump drive or the drive tappet is part of the pump drive.

In the case of a bellows pump, the delivery piston is driven by the drive tappet.

The main plane of the elastic element, in particular a membrane, is understood to mean the plane defined by the annular restraint of this elastic element, in the case of a bellows one of these two planes, which, however, are generally parallel to one another.

The drive tappet and thus, for example, the diaphragm of the feed pump can be set in motion by different drives, be it an electric motor, an eccentric drive, another diaphragm pump or - preferred according to the invention - the piston of a working cylinder, which is preferably operated pneumatically.

The position of the feed pump drive, in particular the drive tappet, is monitored by a position sensor, at least the reaching of its end positions. The position of the feed pump drive, in particular the drive tappet, is preferably detected over the entire movement path.

If the feed pump drive is a working cylinder unit, a distance sensor can be used as the position sensor, which is usually arranged on the rear side of the drive plunger facing away from the pump element, usually the membrane, which in this case is also the piston or the piston rod of the The working cylinder is, and measures the distance of the distance sensor, which is usually fixedly mounted in the cylinder, to this rear side.

The same thing, that is to say a measurement of the axial distance from a distance sensor mounted in a stationary manner, preferably in the working space, can instead or in addition also be provided for the position of the diaphragm of the feed pump.

Alternatively, the lateral surface of the piston could run obliquely to the axial direction of the piston, at least in one area of the circumference, and a distance sensor arranged stationary in the wall of the cylinder could measure the radial distance to this incline, which changes depending on the axial position of the piston . For this, however, the movement path of the piston must not be greater than its axial extent.

Instead or in addition, the same can also be provided for the position of the diaphragm of the feed pump.

The contact surface of the drive plunger, in particular the piston rod of the working cylinder, to the diaphragm is not small and quasi punctiform, viewed in the direction of movement, but rather disc-shaped or ring-shaped with a considerable extent of up to 5%, better up to 10%, better up to to 20%, better up to 25% of the effective surface area of the membrane, that is to say that the material comes into contact during operation, and is preferably arranged centrally. However, the contact area should not be greater than 80%, better not greater than 70%, better not greater than 60%, better not greater than 50%, better not greater than 40% of the effective area of the membrane.

This avoids punctual overloading of the membrane when it is applied.

In addition to the continuous main part of the membrane separating the interior space in the pump housing, the membrane preferably has a concentric, ring-shaped membrane extension on the drive side of the membrane, in particular formed integrally therewith. The annular membrane extension merges with its radially outer edge into the continuous part of the membrane and protrudes from this with its free, radially inner edge and is designed to be resilient in the direction of movement with respect to the continuous main part of the membrane.

The membrane extension is preferably arranged in a ring-shaped circumferential manner between the outer edge and the central region of the main part of the membrane.

A mushroom-shaped membrane support is located as a tension plate with the outer peripheral edge area of its head in the space between the continuous and the annular part of the membrane, and the stem of the mushroom shape extends through the central opening of the annular extension away from the membrane and is releasably connected to the piston rod or directly to the piston of the cylinder, for example screwed.

This means that the membrane can not only be pushed but also pulled. The head of the membrane carrier either sits only in a form-fitting manner between the two parts of the membrane or is firmly connected to one or both of these parts, for example glued.

The continuous main part of the membrane, viewed in a radial section, is preferably designed in such a way that in the unloaded initial state in the central, middle area, in particular in the area of the contact surface, there is a bulge towards the conveying space and / or in the radially outer edge of the membrane, in particular radially away from the contact surface, there is an annular bulge in the direction of the drive space.

This annular bulge is increasingly smoothed and tightened as the diaphragm approaches the feed pump housing and enables the necessary radial length compensation of the diaphragm during operation.

The drive working cylinder is preferably operated pneumatically and therefore has a connection both in its drive space and in its coupling space, i.e. on both sides of the piston of the working cylinder, via which a drive medium, usually compressed air, is used to operate the working cylinder controlled both in the drive space and in the coupling space.

The effective area of the piston of the working cylinder that can be acted upon is preferably greater than the effective area of the diaphragm by at least a factor of 1.4, better by a factor of 1.6, better by a factor of 1.8, better by a factor of 2.0 Diaphragm feed pump.

As a result, even low pressures of the drive medium, mostly air, are sufficient to operate the then pneumatic drive working cylinder.

In addition, the drive space of the feed pump can have a vacuum connection and can be subjected to negative pressure, preferably with the same negative pressure as usually prevails in the storage container to be emptied.

This ensures that the membrane can be actively moved into the fully retracted filling position during the return stroke, and the membrane is not sucked in the direction of the inlet opening by a pressure difference prevailing there in the area of the inlet opening.

A heating device, in particular in the form of electrical heating coils for a heated liquid heating medium or electrical lines, can also be provided upstream of the feed pump housing or in the feed pump housing in order to heat the material to be pumped and thus become more fluid and pumpable to let. Conversely, a cooling device may also be necessary in individual applications, which may include pipelines for a cooled liquid cooling medium.

A liquid sensor is preferably arranged in the drive space of the feed pump, which detects material entering the drive space in the event of a leak, such as a rupture of the membrane, and reports it to the controller, which then emits at least one alarm signal.

At least one pressure sensor can be present in the delivery space of the delivery pump or in its connections in order to know the pressure conditions in the pump and in particular in the delivery space at all times. As a result, an associated control can react to this, either by changing the pre-pressure of the drive medium or, if necessary, by emitting an alarm signal if the measured pressure exceeds a limit value or a minimum pressure is not reached.

However, there is preferably no pressure sensor in the conveying space, above all in order to keep the number of components susceptible to wear low

With regard to the storage device which, in addition to the storage container for the material to be conveyed, comprises at least one of the above-described pump units, this object is achieved in that the pump unit is designed according to one of the preceding claims.

The storage device preferably comprises two such pump units, which can be driven in opposite synchronism in order to ensure a quasi-continuous conveyance of the material into the common outlet line to the consumer.

Preferably, however, the two pump units can be controlled independently of one another, so that temporal overlaps of the return stroke of one pump unit and the working stroke of the other pump unit or a time interval between them can also be achieved.

The feed pump, in particular the diaphragm feed pump, is preferably arranged on the storage device in such a way that its inlet valve is located below the outlet opening of the storage container, so that when the inlet valve is open, the material flows into the pumping chamber of the diaphragm pump solely due to gravity.

The main plane of the diaphragm of the diaphragm feed pump can be inclined at an angle of at most 40 °, better at most 30 °, better at most 20 °, better at most 10 ° to the vertical, while the reservoir preferably stands vertically with its open side up stands in the storage device. This results in a particularly space-saving arrangement and thus a compact storage device.

However, the diaphragm feed pump is arranged horizontally with the main plane of its diaphragm in the bearing device.

The feed pump drive of the one or two feed pumps is preferably arranged on the side facing away from the storage container with respect to the feed pump, so that the pump drive, in particular the drive working cylinder, is easily accessible for repairs.

The tightly closed storage container is preferably subjected to negative pressure in order to prevent air from mixing into the material in the storage container, in particular if the latter is equipped with a mixer.

The air space of the storage container is then preferably connected to the drive space of the feed pump, and this connection can optionally be opened and closed via a valve.

As a result, the same pressure prevails on both sides of the diaphragm in the feed pump, so that when the feed pump is filled, the diaphragm is brought into the optimally close end position to the housing on the drive side and a maximum pump volume is achieved.

• - des Antriebs-Stössels und/oder
• - des den Antriebs-Stössels antreibenden Förderpumpen-Antriebes und/oder
  • - der Membran, insbesondere eines definierten Punktes oder Bereiches der Membran,

direkt oder indirekt ermittelt wird und abhängig davon der Druck des Antriebsmediums, meist Druckluft, mit dem die ihn antreibende Arbeitszylinder-Einheit beaufschlagt wird, gesteuert wird.With regard to the method for operating such a pump unit, in particular in such a storage device, the existing object is achieved in that the axial position of a monitored element, namely

• - the drive tappet and / or
• - The feed pump drive driving the drive plunger and / or
  • - the membrane, in particular a defined point or area of the membrane,

is determined directly or indirectly and, depending on this, the pressure of the drive medium, usually compressed air, with which the working cylinder unit driving it is acted upon, is controlled.

This is necessary because, depending on the current axial position of the membrane, the change in volume in the delivery space is different for each axial distance covered by the delivery pump drive and thus the drive plunger.

The pump unit therefore does not have a constant transmission ratio between the drive pressure and the material pressure in the delivery space, in particular near its outlet opening, over the path of the feed pump drive and thus the membrane.

Therefore, depending on the respective axial position of the drive tappet or, alternatively, the diaphragm, which is axially fixedly coupled to it anyway, at least in the mutual connection area, a different drive pressure or a different drive force must be present on the feed pump drive in order to maintain a constant, especially with regard to the Set height to provide material pressure in the conveying space, in particular near its outlet opening.

The axial position of the monitored element is determined over its entire movement path - continuously or in steps - and the control of the pump unit uses this position signal to depending on this, adjust the drive pressure, which is based on the 4a - d will be explained.

If two or more pump units are present, the ejection movement of the drive plunger of one pump unit is started before the conveying movement of the drive plunger of the other pump unit is ended in order to continuously supply the connected consumer with material with the same To offer material printing.

The drive chamber of the diaphragm feed pump can also have negative pressure applied to it, in particular with the same negative pressure as the air space of the storage container, in particular as soon as the ejection movement of the drive plunger has ended or permanently to prevent deformations of the Avoid diaphragm in the direction of the material inlet opening.

In order to prevent material from flowing back into the inlet opening during the delivery stroke, the inlet valve is closed as soon as the position sensor reports that the drive key has reached its end position and thus the diaphragm of the delivery pump is in the filling position.

If a liquid sensor is present, the controller can report the entry of liquid into the drive chamber upon receipt of a corresponding signal and emit an alarm signal so that the diaphragm pump is repaired, in particular the diaphragm is replaced, or the entire pump unit is replaced with a new one becomes.

As a result, the interruption in operation of the storage device is kept to a minimum, especially since only the actively controllable inlet valve of the corresponding pump unit has to be closed for this and the pump unit can be detached from its connections and removed after completing a last delivery stroke.

If the pump unit contains a pressure sensor in the delivery space - which is not the focus of the invention - the drive pressure could of course be controlled directly on the basis of the measured material pressure, but both the control algorithm for this is complex and the susceptibility of the pressure sensor speaks against it such a solution.

Figure list

• 1a: die Pump-Einheit am Ende des Füll-Hubes,
• 1b: die Pump-Einheiten in Mittelstellung (Normalstellung),
• 1c: die Pump-Einheiten am Ende des Förder-Hubes,
• 2: die gesamte Lagervorrichtung mit einer Pump-Einheit,
• 3a: eine Aufsicht auf den Vorratsbehälter von oben,
• 3b: einen Horizontalschnitt durch den Vorratsbehälter entlang der Linie B - B der 2,
• 4a - d: Kennlinien zum Betrieb der Pump-Einheit.

Embodiments according to the invention are described in more detail below by way of example. Show it:

• 1a : the pump unit at the end of the filling stroke,
• 1b : the pump units in the middle position (normal position),
• 1c : the pump units at the end of the delivery stroke,
• 2 : the entire storage facility with a pumping unit,
• 3a : a plan view of the storage container from above,
• 3b : a horizontal section through the storage container along the line B - B of FIG 2 ,
• 4a - d : Characteristic curves for the operation of the pump unit.

• Die Pump-Einheit 1 besteht dabei aus einer Förderpumpe 1.1 in Form einer Membran-Pumpe, und einer in Bewegungsrichtung 10 der als Pumpelement 3 dienenden Membran 4 dieser Membran-Pumpe koaxial vorgelagerten und damit verbundenen Förderpumpen-Antrieb 8 in Form einer pneumatisch betriebenen Arbeitszylinder-Einheit 1.2, also eines Pneumatikzylinders 8.

The structure of the pumping unit 1 can best be seen on the basis of the sectional view of the 1 detect:

• The pump unit 1 consists of a feed pump 1.1 in the form of a diaphragm pump, and one in the direction of movement 10 as a pumping element 3 serving membrane 4th This diaphragm pump is coaxially upstream and connected to the feed pump drive 8th in the form of a pneumatically operated working cylinder unit 1.2 , i.e. a pneumatic cylinder 8th .

Both the membrane 4th as well as the drive piston arranged coaxially with it 1.2a are designed to be rotationally symmetrical, viewed in the direction of the longitudinal center axis 1' , which are perpendicular to the main plane of the membrane - here running approximately horizontally 4th and the drive piston 1 . 2a is and at the same time the direction of movement of the drive piston 1.2a is.

The funding room 1.1a has an inlet opening in the upper area 5a about which the material M. in the delivery room 1.1a can flow in if that in the inlet opening 5a arranged inlet valve 5 is open, in which case the outlet valve is then usually 6th closed is.

The conveying space is located in the upper area 1.1a furthermore an outlet opening 6a at which an exhaust valve 6th is arranged so that material from this outlet opening M. can flow out when this exhaust valve 6th is open, with the inlet valve then as a rule 5 closed is.

In this way the conveying space becomes 1.1a with material M. filled when the diaphragm 4th from the inlet port 5a moved away (filling stroke) and that in the delivery chamber 1.1a located material M. into the outlet opening 6a ejected when the diaphragm 4th on the outlet opening 6a too moved (conveyor stroke)

The feed pump 1.1 is driven, i.e. its membrane 4th across their main plane 4 ' alternately moved back and forth, by means of one in the middle of the membrane 4th at the rear, i.e. from the drive compartment 1.1b ago, attacking drive tappet 9 .

The feed pump drive 8th in the form of a pneumatic cylinder 8th includes a drive piston 1.2a that is in a drive cylinder 1.2b Can be moved back and forth between two end positions, in particular two stops, preferably in the same direction of movement in which the membrane is also located 4th the one with the feed pump drive 8th coupled diaphragm feed pump 1.1 can move.

The effective area of the drive piston 1.2a however, is larger, about twice as large, selected as that of the membrane 4th in order to with relatively low pressure of the in the drive cylinder 1.2b introduced drive medium, here compressed air, the necessary force on the membrane 4th to be able to raise.

The pneumatic cylinder 8th has a compressed air connection 13th at least as shown on that of the membrane 4th and the feed pump 1.1 remote pressure side of the drive piston 1.2a in the working space of the drive cylinder 1.2b , however, such a compressed air connection is usually also on the other side of the drive piston 1.2a , the tension side, own to the membrane 4th active and thus faster from the inlet opening 5a to be able to withdraw and fill the feed pump 1.1 to accelerate.

The compressed air connection 13th is a proportional valve 18th upstream, which one with the control 1* the pump unit 1 is in connection and can be controlled by this, as described above. This requires constant knowledge of the position of the drive piston 1.2a essential, which is why in the bottom of the drive cylinder 1.2b a position sensor 17th is preferably arranged in the form of a distance sensor that measures the distance between the drive piston 1.2a from the bottom of the cylinder 1.2b measures and to the controller 1* reports.

The pump unit preferably has 1 also via a vacuum connection 12th , in the drive room 1.1b the feed pump 1.1 , whereby the filling process can be supported, especially when the storage container 101 from which the material M. is taken, is also under a negative pressure.

It is preferably in the one of the conveying space 1.1a remote side of the membrane 4th , the drive room 1.1b , a liquid sensor 15th arranged, the material that has penetrated there M. detects what at most a leak in the membrane 4th itself or its circumferential restraint occurs.

The drive piston 1.2a is with the membrane 4th via a drive tappet 9 connected, the centric, that is, along the axial direction 10 running, arranged and with the membrane 4th on the back, i.e. the side of the drive room 1.1b is attached.

• Er umfasst zum einen den Schaft 9.1, der im Wesentlichen den Abstand vom Antriebs-Kolben 1.2a zur Membran 4 überbrückt, sowie einer Druckplatte 9.2, die sich am Membran-seitigen Ende des Schaftes 9.1 befindet und mit einer großflächige Kontaktfläche 9a an der Membran 4 anliegt.

The drive tappet 9 is designed in several parts:

• On the one hand, it includes the shaft 9.1 which is essentially the distance from the drive piston 1.2a to the membrane 4th bridged, as well as a pressure plate 9.2 located at the membrane-side end of the shaft 9.1 and with a large contact area 9a on the membrane 4th is applied.

The membrane 4th When viewed in cross-section, has in addition to the main part that extends between the edge-side restraints 4th an annular appendage 4.1 on the drive side, the inner circumference of which ends freely and the outer circumference of which ends with the rear of the main part 4th is integrally connected.

In the space between the main part 4th and appendix 4.1 there is a tension plate 9.3 , which has a stem centrally on its back, which passes through the opening of the extension 4.1 towards the shaft 9.1 protrudes and is connected to this, is preferably screwed into this.

This tension plate 9.3 can only form a positive fit with the membrane 4th be connected and after changing the membrane 4th re-used, or stuck to the membrane 4th be connected, for example glued, and must then be changed together with this.

The tension plate 9.3 is used to prevent the drive piston from moving backwards quickly, using compressed air 1.2a the membrane 4th with a large attack surface in the form of the appendix 4.1 to be able to withdraw.

The 1a to c show the different functional positions of the drive piston 1.2a as well as the membrane 4th .

• Wenn sich der Antriebs-Kolben 1.2a am Ende des Förder-Hubes befindet, insbesondere an einem am Antriebs-Zylinder 1.2b ausgebildeten axialen Anschlag anliegt gemäß 1c, ist diese Aufwölbung glatt gezogen, und die Membran 4 erreicht fast die Einlass-Öffnung 5a und die Auslass-Öffnung 6a, jedoch nicht bis zu einem Kontakt, um eine Beschädigung der Membran 4 durch die Ränder dieser Öffnungen zu vermeiden.

As can be seen, the drive piston is in the middle position 1.2a according to 1b the membrane 4th slightly arched in the center towards the conveyor room 1.1a in the form of a bulge 4a , and in the edge area between the outer restraint and the one on the tension plate 9.3 adjoining middle part in cross section viewed slightly in the direction of the drive space 1.1b arched in the form of a ring-shaped bulge 4a , creating a radial length reserve for the two end positions:

• When the drive piston 1.2a located at the end of the delivery stroke, in particular on one on the drive cylinder 1.2b formed axial stop is applied according to 1c , this bulge is smoothed, and the membrane 4th almost reaches the inlet opening 5a and the outlet opening 6a but not until contact to damage the membrane 4th by avoiding the edges of these openings.

In the other end position according to 1a , at the end of the filling stroke and the beginning of the delivery stroke, i.e. when the delivery space 1.1a complete with material M. is filled and the piston 1 . 2a at another axial stop of the cylinder 1.2b is applied, the membrane is 4th with its central area further from the inlet opening 5a and the outlet opening 6a removed than the one in the pump housing 2 tightly jammed edge of the membrane 4th so that in the radial area in between in particular the membrane 4th is curved opposite to the curvature in the central, central area.

The inlet valve 5 as well as the exhaust valve 6th is in the 1a - c as an active, i.e. driven, shut-off valve 14th educated.

The exhaust valve 6th can also be used as a simple check valve 7th be trained as in 1b shown by, in this case, a ball as the valve body 7.1 due to gravity on the valve seat pointing upwards 7.2 rests when on both sides of the valve body 7.1 the same pressure prevails, and of course even more so when on the valve seat 7.2 remote side of the valve body 7.1 higher pressure than on the other side.

Because of this, the valve unit should 6th preferably with one with the valve seat 7.2 upward-facing exhaust valve 6th inside the storage device 100 are arranged and preferably lower than the storage container 101 .

The 4a to 4d show how exclusively by means of the monitored axial position of the drive plunger 9 or the drive piston 1.2a the control at the outlet opening as input 6a can provide a constant material pressure that is also predetermined in terms of the absolute height.

A maximum of 10%, better still a maximum of 5%, is permitted as a deviation from the absolute target value. A constant material pressure is understood to mean that the difference between the highest and the lowest value is a maximum of 10%, better a maximum of 5% of the lowest value.

The controller only controls the drive pressure pA of the drive medium, in the control air, with that of the driving pneumatic cylinder 8th , i.e. the drive piston 1.2a in the cylinder 1.2b , is applied.

Because the drive pressure pA is controlled by the position of a pressure regulating valve 18th , here in the form of an electrically operated proportional valve 18th in the supply line for the drive medium, is controlled, the control only changes the current yV with which the electric proportional valve 18th is controlled.

The controller thus controls the drive pressure in the form of the current yV of the electric proportional valve 18th depending on the axial position xK of the drive plunger 9 , especially the piston 1.2a of the working cylinder unit, that is, according to a drive pressure-position characteristic curve, as shown in 4c is shown.

• - entweder in Kenntnis der Form der Membran 4 sowie der Größe des Förder-Raumes 1.1a und des Antriebs-Raumes 1.1b, gegebenenfalls unter zusätzlicher Berücksichtigung der Elastizität der Membran 4 und/oder der Viskosität des zu fördernden Materials M
• - oder in Kenntnis des Übersetzungsverhältnisses der Pumpeinheit 1 an jeder axialen Position xK durch Vergleich von Antriebsdruck pA oder Stromstärke yV mit dem Materialdruck pM.

This drive pressure-position characteristic curve can be determined from a material pressure-position characteristic curve of the material pressure pM over the axial position xK of the drive plunger 9 as in 4b is shown, which in particular by automatic calculation by means of the controller

• - either knowing the shape of the membrane 4th as well as the size of the funding room 1.1a and the drive room 1.1b , possibly with additional consideration of the elasticity of the membrane 4th and / or the viscosity of the material M to be conveyed
• - or knowing the transmission ratio of the pump unit 1 at each axial position xK by comparing the drive pressure pA or current yV with the material pressure pM.

Such a material pressure-position characteristic is recorded at a pumping unit 1 that with a pressure sensor 16a in the delivery room 1.1a is equipped with the drive piston fully retracted 1.2a the working cylinder unit 1.2 and conveying space filled with material 1.1a on the working cylinder unit 8th a constant drive pressure, for example 6 bar, is applied - as in 4a shown - what, for example, with a fully open proportional valve 18th and a corresponding control current yV applied thereto may be the case.

Then, step by step - with pauses of several, in particular at least 5 s, better at least 10 s, better at least 20 s in between - each time a defined withdrawal volume is set material M. from the connected consumer from the delivery room 1.1a taken. As a rule, the material pressure pM drops in each case and increases after the removal process has ended, i.e. when the piston 1.2a has come to a standstill again, again to a material pressure pM which corresponds approximately, but not necessarily exactly, to the material pressure pM present before the removal.

The withdrawal volume should be a maximum of a fifth, better a maximum of a tenth, better a maximum of a twentieth of the entire stroke volume of the feed pump 1.1 correspond.

Between the individual removal steps, the drive piston is at a standstill 1.2a in each case its axial position xK and the associated material pressure pM are measured, which corresponds to the desired material pressure-position characteristic curve 4b in the form of a polygon, which can also be smoothed to a curve by interpolation.

The drive pressure-position characteristic curve converted from this according to 4c is used during operation in such a way that the control current yV corresponding to the axial zero position at the proportional valve before the start of the delivery stroke 18th is set. The drive piston moves when the consumer removes material, either gradually or continuously 1.2a forward.

The pump units used for operation 1 are with the pumping unit 1 , with which the material pressure / position characteristic curve was determined, are identical except for the fact that they do not require a pressure sensor 16.

As soon as a drive pressure-position characteristic according to 4c The axial position of the next pair of values of the polygonal train is reached in the form of a polygon train, is activated on the proportional valve 18th the control current yV is changed to the value of this value pair corresponding to this new axial position and maintained until the axial position of the next value pair of the polygon train is reached.

If the polygon was smoothed into a curve, this adaptation of the control current yV is carried out continuously in accordance with the now curved drive pressure-position characteristic.

• Nach dem Aufzeichnen einer ersten Materialdruck-Positions-Kennlinie bei konstantem Antriebsdruck pA wie oben beschrieben kann dies mehrfach wiederholt werden, allerdings mit manuell an den einzelnen Axialpositionen so verstellten Antriebsdrücken pA das der Abweichung der erzielten Materialdruck-Positions-Kennlinie von einer Horizontalen im Diagramm der 4b entgegengewirkt wird.

The drive pressure-position characteristic required for the control can also be determined experimentally from the material pressure-position characteristic:

• After a first material pressure-position characteristic curve has been recorded at constant drive pressure pA as described above, this can be repeated several times, but with drive pressures pA adjusted manually at the individual axial positions that of the deviation of the material pressure-position characteristic curve achieved from a horizontal in the diagram of 4b is counteracted.

As a result, a horizontal material pressure-position characteristic curve according to 4d can be achieved, and the line pressure-position characteristic with which this is achieved is the desired characteristic according to FIG 4c .

The 2 , and 3a, b show the entire storage device 100 , comprising a pot-like, through a lid 101.2 tightly sealable storage container 101 is present, which is via an inlet port 103 with material M. can be filled or refilled, and the two outlet openings 102 in the ground 108 possesses - as best in the horizontal section of the 3b can be recognized by each of the pump units described above 1 with their inlet port 5a connected.

The at least one inlet opening 103 is positioned so that the material falling down from it M. at a point of impact 110a1 - please refer 3b - on a truncated cone-shaped deflection surface 110a a discharge body 110 meets and on this downwards and radially outwards to the lower drip edge 109 flows in a thin layer and degassed in the process.

Because the wall of the pot 101.1 is not vertical, but is slightly inclined radially upwards and outwards, and the drip edge 109 in the upper area of the storage container 101 near the inner surface 107a the wall 107 the material flows M. from the drip edge 109 down and meets the inner surface 107a the wall 107 where it continues to run down as a thin layer and continues to degas.

The pumping units 1 are symmetrical to the vertical V , the axial direction 101 ' of the storage container 101 , arranged with their membrane planes 4 ' the feed pumps 1.1 lying horizontally.

As a rule, it should be strictly avoided that in the material M. Air enters in the form of air pockets, which is why the storage container 101 is usually hermetically sealed, so the lid shown here 101.2 on the pot 101.1 of the storage container 101 is tightly fastened.

The storage container is in place 101 under a vacuum by placing in the lid of the storage container 101 except for the inlet port 103 also a Vacuum connection 104 - see the supervision according to 3a - is available.

Also show the 2 and 3a also at least one container inlet valve 115 for material M. - of which there may be two in this case according to 3a , for example once to let in new material M. from the storage container 101 and once for the return of recirculated material M. - as well as a viewing window 116 through which into the interior of the storage container 101 can be seen.

How 2 also shows the reservoir can 101 on the one hand a stirrer 106 include, in particular near the ground 108 of the storage container 101 heavy constituents of the material are sedimented by rotation about an upright axis M. prevented.

The motor 111 holding the stirrer 106 drives is complete with its junction box 117 on the top of the lid 101.2 mounted and its motor drive shaft 111a protrudes through this lid 101.2 sealed into the inside of the pot 101.1 into it and is with the upper ends of the impeller 112a , b , c - best see the sectional view of the 3b - connected.

Their vertical arms 118 extend from there downward outward and then parallel to the wall 107 of the pot 101.1 down to near the bottom 108 of the pot 101 , with the vertical arms 118 consist of a flat material, the horizontal cross-section of which is tangential to the longitudinal center axis with its main direction of extent 101 ' , the axis of rotation of the stirrer 106 , so that they generate little drag when rotating.

At the lower end of the vertical arms 118 each is a stir plate 119 arranged at an angle to this, so with a component in the radial direction that achieves a stirring effect, but only just above the bottom 108 .

The impeller 112a - c are for stabilization at the lower end via a cross brace 113 interconnected by attaching them to an annular central plate 113.1 are attached, which leaves a passage from bottom to top in the middle.

A rod-shaped fill level sensor can pass through this passage 114 from the ground 108 from extending upwards.

The discharge body 110 can be fixed on the lid 101.2 mounted or rotating with the stirrer 106 be attached to this, preferably at the top of the impeller 112 a - c .

Furthermore, in the storage container 101 , in particular in its wall, a heating device 107 in the form of e.g. heating wires to be present around the material M. to heat and thereby make it thinner.

List of reference symbols

1

Pumping unit

1'

Longitudinal central axis

1*

control

1.1

Feed pump

1.1a

Funding room

1.1b

Drive room

1.2

Working cylinder unit, drive working cylinder

1.2a

Drive piston

1.2b

Drive cylinder

2

Feed pump housing

3

Pumping element

4th

elastic element, membrane, main part, bellows

4.1

Membrane extension

4a, b

Rejection

4 '

Main level

5

Inlet valve

5a

Inlet opening

5b

Connection piece

6th

outlet valve

6a

Outlet opening

6b

Connection nozzle, outlet nozzle

7th

check valve

7.1

Valve body

7.2

Valve seat

8th

Feed pump drive

9

Drive tappet

9a

Contact area

9.1

shaft

9.2

printing plate

9.3

Tension plate

10

Direction of movement, axial direction

11

vertical

12th

Vacuum connection

13th

Compressed air connection

14th

Lock valve

14a

Valve body

14b

Valve seat

15th

Liquid sensor

16a, b

Pressure sensor

17th

Position sensor

18th

Proportional valve

100

Storage device

100 *

control

101

Storage container

101 '

Longitudinal central axis

101.1

pot

101.2

cover

102

Outlet opening

103

Inlet opening

104

Vacuum connection

105

Vacuum pump

106

Stirrer

107

Wall

107a

Inner surface

108

ground

109

Edge, drip edge

110

Dissipator

110 '

Axis of rotation

110a

Deflection surface

110a1

Impact point

111

Stirrer drive, motor

111a

Motor shaft, output shaft

112a, b, c

Impeller

113, 113a, b, c

Cross bracing

113.1

Central plate

114

Level sensor

115

Inlet valve

116

Viewing window

117

Junction box

118

Vertical arm

119

Stir plate

M.

material

V

vertical

Claims (29)

Pump unit (1) for emptying a storage container (101) filled with liquid or pasty material (M), in particular under negative pressure, in particular a mixing container (101) which is part of a storage device (100), wherein the pump unit (1) comprises a feed pump (1.1) which - a pump element (3) movable relative to the feed pump housing (2) in the direction of movement (10), - a feed pump drive (8), and - has a controller (1 *) for controlling at least all movable components of the pump unit (1), wherein - the pump element (3) at least comprises an elastic element (4), preferably is an elastic element (4), - the feed pump drive (8) comprises a drive plunger (9) which is movable and driven in the direction of movement (10) and which is operatively connected to the elastic element (4), preferably on the side of the drive space (1.1b), thereby characterized in that - a position sensor (17) for determining the respective urgent position of the pump element (3) or the feed pump drive (8), in particular the drive plunger (9), is present along its entire path of movement. Pump unit after Claim 1 , characterized in that - the elastic element (4) is a, in particular, substantially flat, membrane (4) which is tightly attached on its periphery to the inside of the feed pump housing (2) and the feed pump (1.1) is a membrane Feed pump (1.1). Pump unit for according to one of the preceding claims, characterized in that the position sensor (17) is designed as a distance sensor (17) and in particular - is arranged on the rear side of the drive plunger (9) facing away from the pump element (3) and measures the position of the drive plunger (9) and / or - is arranged in the drive chamber of the feed pump (1.1) and measures the axial position of the pump element (3), in particular the membrane (4). (Shape of contact surface) Pump unit for according to one of the preceding claims, characterized in that - the contact surface (9a) of the drive plunger (9) to the elastic element (4) viewed in the direction of movement (10) is disc-shaped or ring-shaped. Pump unit for according to one of the preceding claims, characterized in that - the membrane (4) on the drive side has a membrane extension (4.1) attached to the continuous membrane (4) which, viewed in radial cross section, with the association end to The center of the membrane surface is directed - which is arranged in particular in a ring-shaped circumferential manner between the outer edge and the central region of the membrane (4). Pump unit for according to one of the preceding claims, characterized in that the diaphragm (4) in the radial cross-section in the unloaded initial state - in the outer edge region of the diaphragm (4) has an annular bulge (4a) in the direction of the drive chamber 1.1 and / or - has a bulge (4b) into the conveying space in the central area. Pump unit for according to one of the preceding claims, characterized in that - the conveyor pump drive (8) is a working cylinder unit (1.2) and - the position sensor (17) is a distance sensor (17) which is located in the cylinder (1.2b ) the working cylinder unit (1.2) is arranged and - either measures the axial distance to a rear end face of the drive plunger (9) or the piston (1.2a) of the working cylinder unit (1.2) - or the radial distance to the oblique to the axial direction standing lateral surface of the piston (1.2a) measures. Pump unit for according to one of the preceding claims, characterized in that a pressure sensor (16b) is arranged in the drive space 1.1b of the working cylinder unit (1.2). (Inlet / outlet valve) Pump unit for according to one of the preceding claims, characterized in that the diaphragm feed pump (1.1) - an active, controllably movable inlet valve (5) and / or - a passive outlet valve (6), in particular in the form of a check valve (7), and thereby - in particular the valve body (7.1) is arranged above the valve seat (7.2) of the check valve (7) and the valve body (7.1) by its own weight, in particular only its own weight, and / or an additional closing force, in particular a spring force, is biased into the closed position. Pump unit for according to one of the preceding claims, characterized in that - the inlet valve (5) and outlet valve (6) are arranged on diametrically opposite sides of the delivery space (1.1a) of the membrane delivery pump (1.1). (Vacuum connection) Pump unit for according to one of the preceding claims, characterized in that the drive space (1.1b) of the diaphragm feed pump (1.1) has a negative pressure connection (12) and can be acted upon with negative pressure. (Drive cylinder) Pump unit for according to one of the preceding claims, characterized in that - the drive working cylinder (1.2) can be operated pneumatically and in particular both working spaces (1.2b) of the working cylinder unit (1.2) each via a compressed air connection (13 ), and / or - the effective area of the drive piston (1.2a) of the diaphragm drive pump (1.2) at least by a factor of 1.2, better by a factor of 1.4, better by a factor of 1.6, better by the A factor of 1.8 is greater than the effective area of the diaphragm (4) of the diaphragm feed pump (1.1). Pump unit for according to one of the preceding claims, characterized in that - the feed pump housing (2) has a heating device for heating the interior of the feed pump (1.1), and / or - a liquid sensor (15) on the drive Side of the membrane (4) of the membrane feed pump (1.1) is present and / or - a pressure sensor (16a) is present in the feed space (1.1a) or its connection opening. (Bellows) Pump unit for according to one of the preceding claims, characterized in that - the elastic element (4) is a bellows (4) which connects the feed pump housing (2) to a pump piston (3) and the feed pump (1.1 ) is a bellows pump (1.1). Storage device (100) comprising - a storage container (101) filled with liquid or pasty material (111) in which preferably negative pressure prevails, in particular a mixing container (101), and - at least one pump unit (1) for emptying the Container (100), characterized in that the at least one pump unit (1) is designed according to one of the preceding claims. Storage device according to Claim 15 , characterized in that - the bearing device (100) comprises two pump units (1), which can in particular be controlled independently of one another, and / or - the inlet valve (5) in the diaphragm feed pump (1.1) is lower than the outlet opening (102 ) of the storage container (101) is arranged, and / or - the inlet valve (5) in the assembled state of the diaphragm feed pump (1.1) at the lowest point and the outlet valve (6) at the highest point of its delivery space (1.1 a) is arranged. Storage device according to Claim 15 or 16 , characterized in that - the diaphragm feed pump (1.1) with the main plane (4 ') of the diaphragm (4) at an angle of no more than 40 °, better no more than 30 °, better no more than 20 °, better no more than 10 ° to the vertical ( 11) is arranged, and / or - the at least one feed pump drive (8) is arranged with respect to the membrane feed pump (1.1) on the side facing away from the longitudinal center (101 ') of the storage container (101). Storage device according to Claim 15 , 16 or 17th , characterized in that - a, in particular closable, connecting line between the air space of the storage container (101) and the drive space (1.1b) of the membrane feed pump (1.1), in particular each membrane feed pump (1.1), is present . Method for operating the pump unit, in particular for emptying the storage container (101) of a storage device (100) according to one of the preceding Claims 10 to 14th , characterized in that the axial position of a monitored element, namely - the drive tappet (9) and / or - the feed pump drive (8) driving the drive tappet (9) and / or - the membrane (4), in particular a defined point or area of the membrane (4), is determined directly or indirectly, in particular is determined continuously. Procedure according to Claim 19 , characterized in that the axial position of the monitored element - is determined over the entire movement path and - the control (1 *) of the pump unit (1) uses the position signal to a delivery pressure defined for each axial position, in particular a constant Delivery pressure to be made available at the outlet opening (6a) of the delivery chamber (1.1a). Method according to one of the preceding method claims, characterized in that the target end positions of the membrane (4) and / or the drive piston (1.2a) are determined by defining the end positions of the membrane (4) once during a calibration run. Method according to one of the preceding method claims, characterized in that - the controller (1 *) controls the pump drive (8) by changing a control parameter, in particular - the drive pressure (pA) according to a drive pressure-position characteristic curve between that on the corresponding Drive space (1.1b) of the drive cylinder (1.2) applied drive pressure and the axial position as a monitored element. Method according to one of the preceding method claims, characterized in that the material pressure (pM) is measured, in particular at the outlet opening (6a), and the controller (1 *) controls the pump drive (8) by changing the drive pressure (pA ) according to a drive pressure / material pressure characteristic between the drive pressure (pA) applied to the corresponding working space of the drive cylinder (1.2) and the material pressure (pM). (Safety function) Method according to one of the preceding method claims, characterized in that - the characteristic curve is determined, in particular calculated automatically by the control (1 *) with knowledge of the shape of the membrane (4) as well as the conveying space (1.1a) and the drive Room (1.1b), from an output characteristic curve, - the output characteristic curve is recorded by performing a delivery stroke while keeping the drive pressure (pA) constant and recording the material pressure (pM), at least at individual axial positions of the drive piston (1 2a) over the movement path of the drive piston (1.2a). Method according to one of the preceding method claims, characterized in that the drive pressure is changed by controlling a proportional valve in the supply line for the drive medium. Method according to one of the preceding method claims, characterized in that - the ejection movement of the drive plunger (9) of one pump unit (1) is started before the ejection movement of the drive plunger (9) of the other pump unit ( 1) has ended and / or - the drive space (1.1b) of the diaphragm feed pump (1.1) is subjected to negative pressure, in particular with the same negative pressure as the air space of the storage container (101), in particular as soon as the ejection movement of the drive tappet (9) has ended or is permanent. Method according to one of the preceding method claims, characterized in that the inlet valve (5) is closed as soon as the position sensor (17) reports that the end position of the membrane (4) has been reached by the feed pump (1.1) in the filling position. Method according to one of the preceding method claims, characterized in that the control (1 *) emits an alarm signal as soon as the liquid sensor (15) in the drive space (1.1b) reports liquid to the conveyor pump (1.1). Method according to one of the preceding method claims, characterized in that the control (1 *) stops the feed pump drive (8) as soon as a pressure sensor (16) present in the feed space (1.1a) reports a pressure above a predetermined limit value .

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