EP3594498B1 - System with a recirculation device - Google Patents

Description

The invention relates to a system comprising a process device with a space and / or a line for receiving a gas and a recirculation device for the gas.

the DE 10 2017 212 861 A1 discloses an oil separation device with a drive device which is formed by a side channel pump. the DE 691 13 616 T2 discloses a side channel pump. the DE 25 59 667 A1 discloses a liquid ring seal with a pumpable geometry, the geometry being designed as a side channel pump. the EP 3 176 527 A1 and the EP 2 045 358 A2 disclose systems with a process device and a recirculation device.

Gas recirculation is required in various technical areas. Usually, gas is withdrawn from a larger volume in which a process takes place, processed in a suitable manner and then fed back into the process. To overcome the pressure losses that occur in the gas ducts and any treatment that may be present, a pump is used that can provide the necessary overpressure and volume flow. The properties of the gases or gas mixtures, the general pressure level, the gas volume and the gas temperature are some, but not all, of the parameters that need to be taken into account.

Diaphragm compressors or rotary vane compressors are usually found in such known recirculation devices, sometimes also twin-shaft compressors, such as roots, screw or claw compressors (the terms "compressor" and "pump" are used synonymously herein).

Diaphragm and rotary vane compressors are subject to friction and wear and therefore require regular maintenance. Diaphragm compressors have a pulsating delivery due to discrete pump chamber volumes, poor scalability due to limited speed variability and discrete volumes, wear on bearings, diaphragms, crankshafts, connecting rods and valves as well as vibrations due to the oscillating movement of diaphragms and connecting rods. Rotary vane compressors, depending on their design, have oil or abrasion in the pump chamber, both of which can be disadvantageous for the processes. The limited scalability due to speed due to discrete volumes and friction in the system can also be disadvantageous.

Roots, screw and claw compressors, as non-contact pumps, are less subject to wear, but the manufacturing costs of these twin-shaft systems with synchronous gears are considerably higher. Roots compressors generally have a relatively large size and high costs due to the twin-shaft construction with the required synchronization of the shafts. The compression ratio is relatively low with a relatively large pump space. This means that roots compressors can only be scaled to a limited extent via speed variation. The efficiency is also relatively low because of considerable gap losses. In addition, the shaft bushings would have to be sealed in a complex manner.

In the prior art, a large number of pumps for gas recirculation are known, each of which has specific advantages, but also, as explained, numerous disadvantages.

It is an object of the invention to provide a gas recirculation device in a system of the type mentioned at the outset, which with good effectiveness is carried out simply and inexpensively. In particular, the disadvantages set out above are also intended to be overcome.

This object is achieved by a system according to claim 1, and in particular in that the recirculation pump is a side channel pump. The side channel pump is particularly effective with a simple and inexpensive design in terms of manufacture and operation.

The side channel technology is particularly advantageous due to its flow dynamic properties, the almost mechanically frictionless operation and its adaptability to various processes via speed, side channel and rotor blade geometry, number of stages and a large number of available material combinations. The side channel pump works essentially without contact, thus enabling a long service life and is almost wear-free. The side channel pump allows a needs-based adaptation and precise setting of the provided pressure and flow, e.g. by choosing a single or multi-stage design and / or by means of speed control. Furthermore, a rotor blade shape and a side channel shape can be adapted to the gases to be conveyed. Appropriate resistant materials can be used for corrosive media.

In particular, the side channel pump has only one shaft. A multi-stage side channel pump can also be produced with a single shaft, for example with a plurality of rotors which are arranged on one and the same shaft. The side channel pump is therefore particularly simple and inexpensive to manufacture.

So far, depending on the application, a large number of pumps have been selected so that the specific advantages have been exploited. The inventive The recirculation device now allows a particularly wide range of applications with a simple structure and low manufacturing and operating costs.

The recirculation device can, for example, have a processing device for the gas. The processing device can be designed, for example, to clean the gas, to separate out or enrich certain gas components, to add something to the gas or to make the gas usable for a process in some other way or to improve it.

In general, the gas can only be partially fed back into the process device. For example, all of the withdrawn gas can be returned or only a part, in particular a certain component.

The gas can contain or be, for example, hydrogen, temperature control medium, in particular coolant, and / or CO _2. Furthermore, for example, the gas can contain or be air, helium and / or neon. In general, the gas is present, in particular, at least during operation in the process device, in particular in a room or a line.

The side channel pump can for example comprise at least one rotor with a plurality of rotor blades. It can advantageously be provided that the rotor blades are each at least one of straight, arrow-shaped, curved, divided or connected in the direction of movement, or inclined forwards or backwards in the direction of movement. Combinations of these features per rotor blade, per rotor and / or per pump stage are also advantageous.

An intermediate space between two rotor blades that are adjacent in the direction of movement can, for example, be flat or have a pointed roof-shaped structure. A flat structure is particularly easy to manufacture. A pointed roof-shaped structure supports a vortex formation of the gas to be conveyed in the Side channel and thus the pumping effect. In this case, a ridge edge or a ridge area can for example run essentially parallel to the direction of movement of the blades and / or connect the blades or run at an angle, in particular sloping from one blade to a base of an adjacent blade. The pointed roof-shaped structure can have flat and / or curved, in particular concave, side surfaces.

It can be provided, for example, that at least one side channel of the side channel pump has an at least essentially circular, oval, elliptical, rectangular or egg-shaped cross-sectional geometry. Other cross-sectional geometries are also possible, for example rounded and / or trapezoidal cross-sections. In general, the cross-sectional geometry of a side channel can be symmetrical or asymmetrical, for example.

According to one embodiment, a side channel of the side channel pump tapers in its cross section in the direction of flow, in particular from an inlet of the side channel to an outlet of the side channel. In this way, particularly good compression can be achieved in a simple manner.

In general, a side channel can, for example, be interrupted by a breaker between the outlet and inlet of the side channel or the outlet and inlet can be separated from one another by a breaker.

The side channel pump can preferably have one or more stages, in particular two, three, four or five stages. The steps can be arranged offset axially and / or radially, for example. The performance data of the side channel pump, in particular the discharge pressure and gas flow, can thus be adapted particularly easily to a particular application.

The side channel pump can, for example, have an, in particular hermetic, seal, in particular with respect to the environment. In particular, the parts of the pump that are movable to generate the pumping action, that is to say in particular the shaft, rotor, motor rotor and / or movable bearing parts, can be arranged within the seal, that is to say behind the seal in particular from the perspective of the surroundings. The side channel pump can thus be designed in a simple manner for use with corrosive media. The moving parts can for example be encapsulated for the purpose of sealing.

According to a further development, the side channel pump has a motor with a rotor, the rotor being arranged in a space that is, in particular hermetically, sealed off from the environment. For this purpose, the rotor can in particular be arranged in a tube. For example, the motor can be a canned motor.

Generally advantageously, the motor can be a permanent magnet motor, in particular with a permanent magnet rotor.

The speed of the side channel pump can advantageously be controlled via a frequency converter. The side channel pump can thus be adapted particularly easily and precisely to a particular application and also to certain operating states during a process.

According to one embodiment it is provided that a rotor or a rotor shaft of the side channel pump is supported by at least one grease-lubricated bearing. This enables a low-friction bearing run without an expensive, additional lubrication system. In addition, the bearing can be designed to be so low-maintenance and there is essentially no need to exchange operating media, as would be the case with oil lubrication under certain circumstances.

In general, the pump can have a seal, in particular a hermetic one. In this case, all bearings for the rotor shaft are preferably arranged in the region of the recirculated gas, that is to say behind the seal from the perspective of the surrounding region. In particular, grease-lubricated bearings enable the pump to be sealed as seldom as possible, at best not at all over its service life. In this way, the maintenance effort can be considerably reduced, since the restoration of a seal, in particular a hermetic one, is usually very complex and requires special expertise. In addition, certain gases should not come into contact with the environment for various reasons. This is made much easier by a low-maintenance pump. Generally preferred are the rotor, rotor shaft, motor rotor and / or bearings in the area of the recirculated gas.

The system according to the invention comprises a process device with a space and / or a line for receiving a gas and a recirculation device through which the gas can be removed from the process device and returned to the process device.

The process device is generally designed to carry out a process, the gas being relevant to the process in some way. In general, the gas does not have to be part of the process. The gas can also only act catalytically or in some other way, e.g. be a temperature control medium. The gas can be an essentially pure gas or a gas mixture, such as air. In principle, the gas can also contain particles and / or droplets, for example.

The return of the gas can be carried out, for example, for the purpose of processing, for example cleaning, temperature control, separation and / or enrichment. In particular, the recirculation device can have a correspondingly designed processing device. The return can, however, for example can also be returned essentially without influencing or changing the gas. In general, the gas can be withdrawn, for example, at an outlet of the process device, in particular with only part of the gas flow being returned at the outlet, and / or the gas can, for example, be returned to an inlet of the process device, in particular with a further gas flow entering the inlet.

In particular, the system can be a closed system and / or a closed gas circuit can be provided.

The advantages of the invention are particularly evident in a process device that includes a laser. The laser can preferably be a gas laser, in particular an excimer or CO ₂ laser.

A process device that comprises a temperature control device, in particular an air conditioning and / or cooling device, is also advantageous. In this case, for example, a gas circulation can be brought about by means of the recirculation device. In this way, the temperature control effect of the device can be improved, the advantages according to the invention being particularly well utilized.

The process device can, for example, comprise a fuel cell, which can be used, for example, to generate electricity, for example to drive a vehicle engine. The recirculation device can advantageously be arranged to recirculate excess process gas from the fuel cell, in particular hydrogen.

According to a further advantageous example, the process device comprises a combustion device, in particular an internal combustion engine, for example a vehicle drive. The recirculation device can for example be arranged to recirculate an exhaust gas from the combustion device, in particular to an inlet of the combustion device.

In general, the process device can therefore advantageously be part of a vehicle drive. Furthermore, in general, the process device can comprise, for example, any type of reactor, e.g. fuel cell or combustion device, with at least partially gaseous output.

Finally, all of the embodiments and individual features described for the recirculation device can be used for an advantageous further development of the system, and vice versa.

The invention also relates to the use of a side channel pump as a recirculation pump of a recirculation device for a gas of a process device, in particular a recirculation device according to the invention as disclosed herein, and in particular a recirculation device that is part of a system according to the invention, as disclosed herein.

Fig. 1

zeigt eine Seitenkanalpumpe in perspektivischer Ansicht.

Fig. 2

zeigt die Seitenkanalpumpe der Fig. 1 in einer Schnittansicht.

Fig. 3

zeigt eine weitere Seitenkanalpumpe in perspektivischer Ansicht.

Fig. 4

zeigt die Seitenkanalpumpe der Fig. 3 in einer Schnittansicht.

Fig. 5

zeigt eine dritte Ausführungsform einer Seitenkanalpumpe in einer perspektivischen Schnittansicht.

Fig. 6

zeigt einen gegenüber Fig. 5 vergrößerten Teilbereich der Seitenkanalpumpe in Schnittansicht.

Fig. 7 bis 12

zeigen verschiedene Ausführungsformen von Rotoren für eine Seitenkanalpumpe.

Fig. 13 bis 15

zeigen verschiedene Systeme mit Prozesseinrichtung und Rezirkulationseinrichtung.

The invention is explained below by way of example only with reference to the schematic drawing.

Fig. 1

shows a side channel pump in a perspective view.

Fig. 2

shows the side channel pump of the Fig. 1 in a sectional view.

Fig. 3

shows another side channel pump in a perspective view.

Fig. 4

shows the side channel pump of the Fig. 3 in a sectional view.

Fig. 5

shows a third embodiment of a side channel pump in a perspective sectional view.

Fig. 6

shows one opposite Fig. 5 enlarged partial area of the side channel pump in sectional view.

Figures 7 to 12

show different embodiments of rotors for a side channel pump.

Figures 13 to 15

show various systems with process equipment and recirculation equipment.

Fig. 1 shows a side channel pump 20 for use as a recirculation pump in a recirculation device according to the invention for a gas of a process device. In the upper area, the pump 20 is exposed so that a rotor 22 is visible, which rotates to provide a pumping effect. Out Fig. 2 it can be seen that the pump 20 has only one rotor 22, that is to say is designed in one stage. The rotor 22 rotates with a plurality of rotor blades 24 distributed over its circumference in a side channel 26. The side channel 26 is an annular channel whose cross section is somewhat larger than a respective rotor blade. In the present embodiment, the side channel 26 is essentially rectangular in cross section, but has rounded corners.

The rotor 22 is arranged on a shaft 28 of the side channel pump 20. The shaft 28 and thus the rotor 22 are rotationally driven by an electric motor which comprises a stator 30 and a rotor 32. The stator 30 has energized windings, whereas the rotor 32 in this embodiment has a plurality of permanent magnets. The runner 32 is fixed to the Shaft 28 connected. The shaft 28 and thus the rotor 22 are thus driven directly by the electric motor 30, 32.

In this embodiment, the rotor 22 is designed with curved rotor blades 24 inclined slightly backwards in the direction of movement and with a flat space between the rotor blades 24.

the Figs. 3 and 4 show a two-stage side channel pump 20 which has two rotors 22.1 and 22.2 which are mounted on a common shaft 28. The rotors 22.1 and 22.2 rotate in respective side channels 26.1 and 26.2, which here also have an essentially rectangular cross section. In the upper area of the Fig. 4 a connection 34 of the side channels 26.1 and 26.2 is visible.

The rotors 22.1 and 22.2 each have arrow-shaped blades 24 which are inclined slightly backwards in the direction of movement. In the spaces between the blades 24, the rotor 22 is each flat. The direction of movement here preferably runs in the direction of the tips of the respective arrow-shaped blades 24. In principle, however, reverse operation is also possible, for example.

The shaft 28 which carries the rotors 22 is driven by an electric motor. The electric motor has a stator 30 with windings and a permanent magnetic rotor 32 which is seated on the shaft 28. The rotor 32 and the shaft 28 are arranged within a tube 36 which is part of a hermetic seal for the pump 20. Such a tube 36 is also referred to as a can, since it extends through the gap between the rotor 32 and the stator 30 of the electric motor. Correspondingly, the electric motor is referred to as a canned motor. The can 36 can be made of fiberglass composite, for example. The rotor 32 and the shaft 28 are therefore off View of the surroundings behind the hermetic seal and in an area which is essentially penetrated by the gas to be conveyed by the pump and has a corresponding pressure level.

There are also two bearings 38 behind the seal or in the area of the gas to be conveyed. These are preferably grease-lubricated and / or permanently lubricated.

The functional elements arranged in the gas area or behind the seal are therefore essentially capable of functioning independently. In particular, they do not have to be supplied via a line, for example with electricity or equipment. The rotors 22 also run without contact in the housing gaps 40 provided for them. The functional parts in the gas area are therefore extremely wear-resistant and require little maintenance. The hermetic seal of the pump 20 therefore only has to be broken very rarely during dismantling in order to service the pump.

A third embodiment of a side channel pump 20 is shown in FIG Fig. 5 shown. The side channel pump 20 is designed in five stages, that is to say five rotors 22 are provided which rotate in respective side channels 26. The rotors 22 are in turn arranged on a common shaft 28. An in Fig. 5 The indicated area A of the side channel pump 20 is shown in FIG Fig. 6 shown enlarged and rotated by 90 degrees.

Out Fig. 6 it can be seen that the side channels 26.1 and 26.2 of the first two pump stages are essentially rectangular, whereas the side channels 26.3, 26.4 and 26.5 of the other pump stages have an essentially oval or egg-shaped cross section. How it looks in particular Fig. 5 As can be seen, the rotors 22.1 and 22.2 each have curved rotor blades. The rotors 22.3, 22.4 and 22.5, however, are arrow-shaped. The rotors 22.3, 22.4 and 22.5 also have a pointed roof-shaped structure 42 in the respective intermediate spaces between adjacent rotor blades 24, which supports the pumping effect by promoting a vortex formation of the gas flow in the side channel 26.

In the Figures 7 to 12 various advantageous embodiments of rotors 22 are shown. The rotor 22 of the Fig. 7 has curved rotor blades 24 with shallow spaces.

The rotor 22 of the Fig. 8 has planar rotor blades 24 that extend radially. Roof-like structures 42 are provided between the rotor blades 24, a respective ridge edge 44 extending parallel to the direction of movement of the rotor blades 24. The ridge edge 44 connects radially outer ends of the blades 24. These are thus connected rotor blades 24. The surfaces 46 tapering towards the ridge edge 44 are concave.

The rotors 22 of the Figures 9 to 11 are all arrow-shaped and differ essentially in size and number of blades or relative blade spacing. They also have a roof-like structure 42 with a respective ridge edge 44 in the space between the blades. The ridge edges 44 of the rotors 22 are the Figures 9 and 10 itself is curved, whereas the ridge edge 44 in Fig. 11 is essentially straight. All ridge edges 44 of the Figures 9 to 11 extend from a respective blade tip to a bottom of an adjacent blade. The rotor blades 24 are therefore not connected.

The blades 24 of the rotor 22 of in Fig. 12 The embodiment shown are ultimately curved, and they differ in particular in terms of number and size from the embodiment of FIG Fig. 7 differentiate.

In Fig. 13 a system with a process device 50 and a recirculation device 52 is shown, the recirculation system 52 being a Has side channel pump 20 trained recirculation pump. The process device 50 has an inlet 54 and an outlet 56. The inlet 54 is connected to the recirculation device 52 in such a way that a returned gas is fed back into the inlet 54. A further mass flow is also fed to the inlet 54 via a further line. In a similar way, the outlet 56 is connected both to the recirculation device 52 or the side channel pump 20, as well as to a further line which takes up a partial mass flow of the outlet 56. In the system of Fig. 13 a part of a mass flow that passes through the process device is therefore recirculated. The process device 50 can be a fuel cell, for example. In this case, the mass flow can contain hydrogen, for example. Excess hydrogen, which has not been consumed by the fuel cell, is returned to the inlet 54 via the recirculation device 52 in order to be consumed after all. Thus, the efficiency of the fuel cell can be improved. In particular, a separator can be provided downstream of the outlet 56, which separator supplies the side channel pump 20 with as large a portion of the excess hydrogen as possible.

The process device 50 of the system of Fig. 13 can for example also be a combustion device such as an internal combustion engine. The recirculation device 52 forms an exhaust gas recirculation in that it takes exhaust gas from the mass flow of the outlet 56 and returns it to the supply air flow at the inlet 54.

Fig. 14 shows a closed system with regard to the gas flow with process device 50 and recirculation device 52 with side channel pump 20. The gas in process device 50 can be circulated via recirculation device 52 and its side channel pump 20, for example to avoid phase formation of a gas mixture in the process device.

Another system that is closed with regard to the gas flow is shown in FIG Fig. 15 . This system also comprises a process device 50, a recirculation device 52 and a side channel pump 20. The recirculation device 52 of FIG Fig. 15 also comprises a processing device 58 for processing the returned gas. The processing device 58 can be designed for cleaning and / or temperature control of the gas, for example. A processing device can, for example, be part of the recirculation device of Fig. 13 being. To that extent in connection with the systems of Figures 14 and 15 When talking about closed systems, it goes without saying that the purely schematic drawings do not exclude other gas and pipe systems.

In the figures, only embodiments are shown in which the side channels or the side channel pump stages are arranged axially offset. It goes without saying that the side channel pump of the recirculation device according to the invention can also have, for example, radially offset side channel pump stages. A combination of axially and radially offset steps is also possible. Finally, the side channel pump can also be advantageously connected to pump stages which have different pump principles.

List of reference symbols

20th

Side channel pump

22nd

rotor

24

Rotor blade

26th

Side channel

28

wave

30th

Stand

32

runner

34

connection

36

Can

38

warehouse

40

gap

42

Pointed roof-shaped structure

44

Ridge edge

46

surface

50

Process setup

52

Recirculation device

54

inlet

56

Outlet

58

Processing facility

Claims (15)

1. A system comprising

   a processing device (50) having a space and/or a line for receiving a gas; and

   a recirculation device (52) through which the gas can be removed from the processing device (50) and can be returned into the processing device (52), wherein the recirculation device (52) comprises a recirculation pump, characterized in that

   the recirculation pump is a side channel pump (20).
2. A system in accordance with claim 1,
   wherein the gas includes hydrogen, a temperature control medium and/or CO₂.
3. A system in accordance with one of the preceding claims,
   wherein the side channel pump (20) comprises at least one rotor (22) having a plurality of rotor blades (24); and wherein the rotor blades (24) are each at least one of straight, oblique, arrow-shaped, curved, divided, undivided, or inclined to the front or to the rear in a direction of movement.
4. A system in accordance with any one of the preceding claims,
   wherein the side channel pump (20) comprises at least one rotor (22) having a plurality of rotor blades (24); and wherein an intermediate space between two rotor blades (24) adjacent in the direction of movement is flat or has a pointed roof-shaped structure (42).
5. A system in accordance with any one of the preceding claims,
   wherein at least one side channel (26) of the side channel pump (20) has a circular, oval, elliptical, rectangular or egg-shaped cross-sectional geometry.
6. A system in accordance with any one of the preceding claims,
   wherein at least one side channel (26) of the side channel pump (20) tapers in its cross-section in a flow direction.
7. A system in accordance with any one of the preceding claims,
   wherein the side channel pump (20) has a single-stage or multi-stage design.
8. A system in accordance with any one of the preceding claims,
   wherein the side channel pump (20) has a seal; and wherein the parts of the pump (20) which are movable to produce the pumping effect are arranged within the seal.
9. A system in accordance with any one of the preceding claims,
   wherein the rotational speed of the side channel pump (20) is controllable via a frequency converter.
10. A system in accordance with any one of the preceding claims,
    wherein a rotor (24) of the side channel pump (20) is supported by at least one grease-lubricated bearing (38).
11. A system in accordance with any one of the preceding claims,
    wherein a closed gas circuit is provided.
12. A system in accordance with any one of the preceding claims,
    wherein the processing device (50) comprises a laser.
13. A system in accordance with any one of the preceding claims, wherein the processing device (50) comprises a temperature control apparatus.
14. A system in accordance with any one of the preceding claims, wherein the processing device (50) comprises a fuel cell.
15. A system in accordance with any one of the preceding claims, wherein the processing device (50) comprises a combustion device.

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