EP2756879A1 - Method and apparatus for introducing gas into a liquid - Google Patents

Abstract

The device has a mixing unit arranged in a mixing container (2) and comprising a spinner wheel with a radially arranged suction opening for flowing gas into the mixing container. A pump (3) is operated by a motor (3a) and arranged in the container. The spinner wheel comprises gas chambers, and a central gas-distribution chamber for distributing gas into the gas chambers is arranged at the spinner wheel. A spinner wheel arbor is connected with the spinner wheel and with a drive shaft. A side wall of one of the gas chambers is designed with linear cross-section. An independent claim is also included for a method for introducing gas into fluid.

Description

The invention relates to a device for introducing gas into a liquid according to the preamble of claim 1 and to a method for introducing gas according to the preamble of claim 10.

For finding leaks in liquid-carrying lines, it is known to introduce a gas, for example helium, into the liquid and to introduce it together with the liquid into the line to be tested. The helium exits at a damaged point on the line and can be located by detectors. This makes it possible to locate the damaged area very accurately and to repair specifically.

For introducing a gas into a liquid is from the DE 28 26 259 For example, a nozzle device with a plurality of mixing chambers is known, in which the liquid is introduced and mixed together with the gas. From the US 5049 320 Again, it is known to pass the gas through a filter fabric in the liquid.

The known devices, however, have numerous disadvantages. Thus, for the leak detection by the known devices, no sufficiently uniform distribution of the gas in the liquid, so that the amount of gas in the liquid must be increased. It also takes too long to produce the amount of gasified liquid needed for leak detection. In addition, for example, clogged nozzles often lead to further delays, which make leakage detection significantly more difficult.

In addition, nozzle-based gas enrichment systems are extremely cumbersome, bulky, and unsuitable for mobile use, while leak detection gas-enrichment systems are mobile, easily transportable, and thus space-saving and easy to access and easy to damage / maintain must be repairable.

The invention is therefore based on the object of proposing a method and a device for particularly uniform and rapid mixing of a gas with a liquid that is portable.

The invention achieves the object by a device having the features of claim 1 and a method having the features of claim 10. Advantageous developments of the invention are specified in the independent claims.

The device according to the invention has a mixing unit arranged in a mixing container with a centrifugal wheel arranged on the mixing unit with a radially arranged outlet opening for the outflow of a gas into the mixing container.

For introducing the gas into the present in the mixing vessel, inflowing or the mixing vessel by flowing liquid gas is introduced into the mixing unit and in the impeller. Due to the rotational movement of the impeller, the gas is introduced by the resulting centrifugal forces from the outlet opening of the impeller at a high speed in the liquid. As a result, a particularly rapid and uniform gas enrichment of the liquid is achieved, so that it is possible to sufficiently mix a liquid flowing through the mixing container with gas in order to be able to carry out a subsequent leak detection of the line through which the gas-enriched liquid flows. The achievable by the inventive device homogeneous and fine distribution of the gas in the liquid makes it possible to keep the absolute amount of gas / liter of liquid particularly low, which allows a particularly cost-effective operation of the mixing unit.

The rotational speed of the impeller is flexibly adjustable, with an operation with continuously changing speed is possible. As a result, the gas quantity / time unit to be introduced can be varied very precisely, so that it is also possible to apply particularly large amounts of gas in a basically arbitrary liquid, for example water, with a particularly compact and small installation space ,

Under a mixing container is in the sense of the application, a mixing vessel, ie a container understood, in which the mixing process between the liquid and the gas takes place. This is usually a closed boiler. Advantageously, the boiler can be heated, for example, because the gas absorption capacity of liquids is influenced by the elevated temperatures. Also, a sealed boiler prevents the escape of gas, eg. Helium from the liquid.

The mixing unit has a drive unit, for example a motor and a drive shaft driven by the motor and connected to the blower wheel. The drive unit displaces the blower wheel, which is preferably arranged at one end of the mixing unit, into a rotary movement.

The mixing unit is designed for receiving, for example, for sucking in or for introducing the gas. For this purpose, the drive shaft, via which this is mixed with the liquid, for example. Tubular, i. be designed to flow through the gas. From the drive shaft, the gas flows into the impeller. For receiving the gas in the spinner, this has a gas chamber and is thus formed as (at least partially) hollow body. In addition to the rotational speed, additional mixing effects can be achieved via the basically arbitrary outer geometry of the centrifugal wheel in order to achieve a particularly effective and fine gas distribution. The gas chamber may, for example, be annular and extend over the entire circumference of the blast wheel. Also, the gas chamber may extend only partially, for example, as a radially extending bore above the spinner radius. Also, the blast wheel may have an asymmetrical shape and / or mixing elements arranged on the outside, which lead to a higher turbulence.

As a result of the rotational movement of the centrifugal wheel during operation and the resulting centrifugal forces in the centrifugal wheel, the gas is thrown out of the centrifugal wheel, starting from the gas chamber through the radial outlet opening.

To ensure that as much gas as possible exits the centrifugal wheel during the radial movement at all times, the centrifugal wheel according to an advantageous development of the invention has at least two gas chambers each with a radial outlet opening. Alternatively, for example, three, four or more gas chambers, each with its own radial outlet opening be arranged.

The gas chambers are advantageously uniform in size, separated by webs and extending in the radial direction of the spinner. The chambers are preferably arranged around a central axis, for example, about a central gas inlet opening on the blast wheel.

In order to achieve a particularly good distribution of the gas in the impeller, in particular in an embodiment with a plurality of gas chambers, the impeller according to an advantageous embodiment of the invention, a central gas distribution space for distributing the gas into the gas chambers. As a result, a particularly uniform filling of the gas chambers is achieved.

The gas distribution space is advantageously central, i. arranged centrally in the impeller and is on the one hand in direct communication with the inlet opening for the flow of gas into the gas distribution space and on the other in direct communication with the gas chamber / n. In this way, a particularly compact centrifugal wheel can be provided, which ensures a very uniform outflow of the gas from the impeller. This in turn makes it possible to design the mixer unit particularly compact, which allows the production of particularly space-saving devices.

In order to increase the amount of gas to be introduced into the liquid and to achieve a further improvement in the quality of distribution of the gas in the liquid, according to one embodiment of the invention, the impeller has an additional vertical outlet opening for discharging the gas into the mixing vessel. In this case, a vertical outlet opening is understood as meaning an outlet opening extending in the direction of rotation of the spinner wheel. It may, for example, be arranged on the side of the centrifugal wheel opposite the inlet opening. Also, you can directly opposite the entrance opening, whereby a particularly compact design of the impeller is made possible.

The outlet opening is, for example, via a channel with the inlet opening in connection. Also, the vertical outlet opening, for example. With the gas distribution space in combination be or be part of.

According to a development of the invention, the gas distribution space has a frustoconical shape. The gas distribution space expands, starting from the inlet opening to the side of the centrifugal wheel opposite the inlet opening, for example a vertical outlet opening.

In particular, when the vertical exit opening is part of the gas distribution space, the frusto-conical shape ensures a particularly wide exit of the gas into the liquid, d. H. the gas is introduced from the vertical outlet opening into a large liquid area. In addition, the frusto-conical shape promotes a slight inflow of the gas into the radial gas chambers.

In order to further improve the distribution of the gas in the liquid, i. To achieve the most uniform distribution in a particularly short time, a high degree of turbulence in the liquid and in the gas is of particular advantage. In order to increase in particular the degree of turbulence of the gas, a first side wall of the gas chamber extending from the radial outlet opening to an inlet opening of the gas chamber is particularly preferably arcuate in cross section and a second side wall of the gas chamber extending from the radial outlet opening to the inlet opening is linear in cross section educated.

A side wall is thus flat (flat) while its opposite side wall has an (at least partially) convex or concave shape. Surprisingly, this achieves a significantly improved gas uptake of the liquid and a particularly uniform gas distribution in the liquid, which is attributable to the increase in the degree of turbulence of the gas / liquid.

Particularly preferably, the inlet opening is formed drop-shaped in cross section in the gas chamber. As a result, the gas during operation, that is, upon rotation of the impeller facilitates the flow into the gas chamber, so that a higher amount of gas / time unit can flow through the gas distribution space and thus through the impeller.

In order to facilitate the replacement of the impeller in, for example. Damage or for maintenance, the device particularly preferably has a trained for connection to the impeller and a drive shaft Schleuderraddorn.

The spinner wheel is disposed between the drive shaft and the spinner. It can extend the drive shaft to position the spinner lower in the mixing bowl. For example, it is possible to use differently long sprocket spikes when using different mixing vessel heights.

The spinner wheel has a gas passage line which can be connected in a gastight manner to the gas line in the drive shaft and to the inlet opening in the spinner wheel. For a particularly durable (low-maintenance, little repair-prone) connection of the centrifugal mandrel according to a further embodiment of the invention in the drive shaft is inserted and formed via a quick coupling with this fixable.

The quick coupling is formed with a bolt as a connecting means to achieve a particularly simple fixation of the centrifugal mandrel on the drive shaft. The bolts are diagonally upwards, i. in the direction of the gas line and in the direction of the drive unit in the drive shaft screwed. An inserted into the drive shaft Schleuderraddorn is firmly pressed by the acting on him bolts (gas-tight) in the drive shaft.

The object of the invention is further achieved by a method for introducing a gas into a liquid with a blast wheel, wherein the gas is introduced in the radial direction of the impeller and by means of a centrifugal force in the liquid.

By introducing the gas in the radial direction and the high speed, which receives the gas by the rotational movement of the impeller, the gas is distributed in a very large area around the impeller and mixed with the liquid. In addition, there is a particularly fine and uniform distribution of the gas in the liquid, so that for the leak detection, the amount of gas / liter of liquid can be particularly low. As a result, in particular high costs for the provision of the gas can be saved. Furthermore, the blast wheel allows to provide a particularly compact and thus portable (mobile) gas enrichment plant.

Due to the variable and independent configurability of the flow rate of liquid through the mixing container and of gas through the mixing unit, it is also possible to introduce a very compact mobile system a large amount of gas in a very short time in the liquid, causing the leak detection Necessary quantities of gasified liquid can be generated in lines.

Fig. 1

in perspektivischer Darstellung eine schematische Ansicht einer Ausführungsform einer Anlage zum Anreichern einer Flüssigkeit mit Gas;

Fig. 2

in einer perspektivischen Darstellung eine schematische Ansicht einer Ausführungsform einer Mischeinheit aus Fig. 1;

Fig. 3

schematisch einen Querschnitt durch eine Mischeinheit aus Fig. 2;

Fig. 4

in perspektivischer Darstellung einer schematischen Ansicht einer Ausführungsform eines Schleuderrades;

Fig. 5

schematisch einen Querschnitt durch ein Schleuderrad aus Figur 4.

Furthermore, the invention will be described in more detail with reference to several embodiments. It shows:

Fig. 1

in perspective view a schematic view of an embodiment of a system for enriching a liquid with gas;

Fig. 2

in a perspective view of a schematic view of an embodiment of a mixing unit Fig. 1 ;

Fig. 3

schematically a cross section through a mixing unit Fig. 2 ;

Fig. 4

in a perspective view of a schematic view of an embodiment of a blast wheel;

Fig. 5

schematically a cross section through a blast wheel FIG. 4 ,

In a perspective view shows FIG. 1 a transportable plant 1 for enriching a liquid with a gas. The plant 1 comprises a vessel-shaped mixing vessel 2, in which a liquid can be introduced via a pump 3 operated by a motor 3a.

On the top of the mixing container 2 is a mixing unit 10 (see Fig. 2 ) driving drive unit 5 with a drive motor 5a, a V-belt (not shown) and a V-belt pulley 15 (see FIG. 2 ) arranged.

The mixing container 2 has, in the region of its bottom, an outlet valve 4, from which the liquid enriched in the mixing container with a gas can, for example, be fed into a line (not shown here) to be examined for leakage. Further, a plurality of sight glasses 9 and a temperature indicator 9 a for displaying the temperature prevailing in the mixing container 2 are arranged in the wall of the mixing container 2.

The mixing container 2 and the motor-driven pump 3 are mounted on a basic frame 6 for particularly easy transport. Furthermore, a switching unit 7 designed for controlling the system 1 and a gas unit 8 are arranged on the basic frame 6, whereby a compact enrichment system 1 is created, which can be used in a particularly flexible and location-independent manner.

The FIG. 2 shows the mixing unit 10 with the V-belt pulley 15, a drive shaft 11, a sprocket wheel 12 connected to the drive shaft 11 and a blast wheel 13 connected to the sprocket wheel 12.

The drive shaft 11 is rotatably supported by the V-belt pulley 15 in a bearing housing 16. Below the bearing housing 16, a connecting flange 14 for connecting the mixing unit 10 with the mixing container 2 is arranged.

On the outer side of the bearing housing 16, a gas inlet valve 18 is arranged, via which the gas to be introduced into the liquid is introduced into the bearing housing 16. Above and below the gas inlet valve 18 are arranged lubricant valves 19a, 19b for introducing lubricant, via which a bearing housing 16 arranged in the drive shaft bearing 21a, 21b (see FIG. 3 ) is supplied with lubricant.

The drive shaft 11 exits from the bearing housing 16 below the connecting flange 14 and, in the mounted state of the mixing unit 10, is located on the mixing container 2 within the mixing container 2.

The subsequent to the drive shaft 11 Schleuderraddorn 12 is connected to a first end via a quick coupling 17 gas-tight with the drive shaft 11. At the second end of the spinner wheel 12 opposite the first end, the spinner wheel 13 is detachable from the spinner wheel 12 and likewise fixed in a gas-tight manner. The quick coupling 17 allows a particularly simple replacement of the Schleuderraddorns 12 and the impeller 13th

FIG. 3 shows the mixing unit 10 in cross section. The mixing unit 10 is bolted via its connecting flange 14 with the mixing container 2. The V-belt pulley 15 is connected to the Drive shaft 11 connected, the drive shaft 11 is rotatably supported in the bearing housing 16 via two slide bearings 21a, 21b. The spinner 12 and the spinner 13 are arranged inside the mixing container 2.

The drive shaft 11 has a gas line 20, which is arranged centrally in the drive shaft 11 and is in communication with the gas inlet valve 18. The spinner wheel 12 is connected to the drive shaft 11 via the quick coupling 17. The quick coupling 17 is designed as a detachable screw connection with diagonal upward, i. formed in the direction of the gas line 20 and the V-belt pulley 15 pointing bolts which are screwed into the drive shaft 11 and engage in the Schleuderraddorn 12.

A likewise centrally arranged in the spinner wheel 12 gas passage line 22 adjacent in the region of the quick coupling 17 gas-tight to the gas line 20 of the drive shaft 11 and in the region of the impeller 13 also gas-tight to a (gas) inlet opening 27 of the impeller 13, so that one over the Gas valve 18 in the bearing housing 16 introduced gas flows through the gas line 20 and through the gas passage line 22 directly into the inlet opening 27 of the impeller 13.

The inlet opening 27 in the centrifugal wheel 13 opens into a central gas distribution space 23. The gas distribution space 23 is adjoined by four radially extending gas chambers 24, each of which has a radial outlet opening 25. The number of gas chambers 24 can be designed flexibly. Thus, for example, only one, two or three gas chambers 24 or, for example, five or more gas chambers 24 may be formed.

The central gas distribution space 23 is formed as an open space in the longitudinal axis direction of the mixing unit 10, that is, the gas distribution space 23 has a vertical exit opening 26 extending in the longitudinal axis direction in addition to the radial exit openings 25 of the gas chambers 24.

FIG. 4 shows the blast wheel 13 in a perspective view. The impeller 13 is in three parts -but formed in one piece and consists of an upper centrifugal disc 35, a lower centrifugal ring 36 and the centrifugal disc 35 and the slinger 36 connecting webs 32. The centrifugal wheel 13 has, as already mentioned above four gas chambers 24, which are formed by a lower side of the upper centrifugal disk 35, an upper side of the lower centrifugal ring 36 and the side surfaces (flanks 24a, 24b) of the webs 32. The upper centrifugal disc 35 has a centrally arranged connecting element 33 for connecting (screwing) the upper centrifugal disc 35 to the centrifugal mandrel 12. The slinger 36 has a centrally disposed vertical outlet opening 26.

Starting from the bottom 28 of the slinger 36, the vertical outlet opening 26 has a chamfer 29 (alternatively, for example, a rounding). The central gas distribution space 23 adjoining the chamfer 29 has a tapering frustoconical shape in the direction of the centrifugal disk 35.

Due to the truncated cone-like shape and the chamfer 29, a particularly wide distribution of the gas emerging from the outlet opening 26 is achieved, as a result of which the gas is distributed particularly easily and uniformly in the liquid.

On the lateral surface 30 of the truncated cone-like gas distribution chamber 23 (gas chamber) inlet openings 31 are arranged. The gas flowing into the gas distribution space 23 through the inlet opening 27 penetrates through the inlet openings 31 into the gas chamber 24, flows through the latter and enters from the radial outlet opening 25 directly into the liquid present in the mixing tank 2.

In operation, the impeller 13 600 ^U / _min rotates at a speed of, for example, wherein 300 to 1000 ^U / _min, the gas introduction may be kept constant, preferably because of the changing conditions due to temperature variations and varying process pressure by rotation speed adjustments in the range of. The gas is preferably pressed into the gas distribution space 23 with a pressure exceeding the water pressure in the container by approximately 0.5 bar. In order for the gas to penetrate into the gas chambers 24 in a particularly simple manner in a large quantity and to achieve a high degree of turbulence and thus a more uniform mixing of the gas flowing out of the gas chambers 24 with the liquid, a respective first flank 24a has the gas chamber 24 an arcuate and a second flank 24b of the gas chamber 24 has a linear cross-section. This results in the region of the inlet opening 31 a drop shape that promotes the influx of gas into the gas chamber 24. By turning the mixer, the water inside is catapulted to the outside and sucks through the opening 31 new water from below into the spin gap between the flanks 24a, 24b.

FIG. 5 shows the spinner 13 schematically in horizontal section. The blower wheel 13 has four gas chambers 24 of equal size arranged centrally around the inlet opening 27. The gas chambers 24 are separated by webs 32. The side surfaces of the webs 32 form the flanks of the gas chambers 24a, 24b. Also centrally around the inlet opening 27 are four screw through holes (connecting element 33) for screwing the Schleuderraddorns 12 is formed.

On the top of the upper centrifugal disc quarter-spherical recesses 34 are arranged which cause an additional turbulence of the liquid and thus an improved gas absorption capacity of the liquid.

LIST OF REFERENCE NUMBERS

1

investment

2

mixing tank

3

pump

3a

engine

4

outlet valve

5

drive unit

5a

drive motor

6

backbone

7

switching unit

8th

gas unit

9

sight glasses

9a

temperature display

10

mixing unit

11

drive shaft

12

Schleuderraddorn

13

blower

14

connecting flange

15

pulley

16

bearing housing

17

Quick connectors

18

Gas inlet valve

19a, 19b

lubricant valves

20

gas pipe

21a, 21b

Drive shaft bearing / bearings

22

Gas transit line

23

Gas distribution space

24

gas chambers

24a, 24b

flanks

25

radial outlet opening

26

vertical outlet

27

(Gas) inlet opening

28

bottom

29

chamfer

30

lateral surface

31

(Gas chamber) inlet openings

32

Stege

33

connecting element

34

recesses

35

slinger

36

slinger

Claims (10)

Device for introducing gas into a liquid with a mixing unit (10) arranged in a mixing container (2), which has a centrifugal wheel (13) with a radially arranged outlet opening (25) for discharging a gas into the mixing container (2). Apparatus according to claim 1, characterized in that the impeller (13) has at least two gas chambers (24) each having a radial outlet opening (25). Apparatus according to claim 1 or 2, characterized in that the centrifugal wheel (13) is arranged a central gas distribution space (23) for distributing the gas into the gas chambers (24). Device according to one of the preceding claims, characterized in that the centrifugal wheel (13) has a vertical outlet opening (26) for the outflow of the gas into the mixing container (2). Device according to one of the preceding claims, characterized in that the gas distribution space (23) has a frustoconical shape. Device according to one of the preceding claims, characterized in that starting from the gas distribution space (23) is formed an inlet opening (31) for flowing the gas into the gas chamber (24). Device according to one of the preceding claims, characterized in that - A first extending from the radial outlet opening (25) to the inlet opening (31) extending side wall (24a) of the gas chamber (24) is arcuate and / or - A second extending from the radial outlet opening (25) to the inlet opening (31) extending side wall (24b) of the gas chamber (24) is formed linearly in cross section. Device according to one of the preceding claims, characterized in that the inlet opening (31) is drop-shaped. Device according to one of the preceding claims, characterized in that for the connection with the centrifugal wheel (13) and with a drive shaft (11) formed Schleuderraddorn (12) is arranged. Method for introducing a gas into a liquid, comprising a blast wheel (13), wherein the gas is introduced into the liquid in the radial direction of the blast wheel (13) and by means of a centrifugal force.

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