DE9207094U1 - Device for gassing liquids - Google Patents

Description

Keil&Schaafhausen

PATENT ATTORNEYS

Frankfurt am Main 22.05.1992
Sch 50 G 4 CIP

Karl-Heinz Schuessler

Tannenwaldallee 72

6380 Bad Homburg v.d.H.

Device for gassing liquids

Description:

The invention relates to a device for gassing liquids, in particular for aerating waste water, by means of a gas distributor which can be arranged below the liquid level and connected to a gas supply device and which has at least one membrane-like wall made of flexible material with a plurality of gas outlet openings.

It has been proposed that such a gassing device be manufactured cost-effectively with low material requirements and simple maintenance by designing the wall as a support-free bubble that is only held in place by a gas supply nozzle and is closed except for a gas supply opening and the gas outlet openings. In principle, the gas distributor consists only of the bubble and has neither an internal nor an external support structure. However, it has been found that the gas bubbles rise relatively quickly to the liquid level after they leave the bubble and therefore only a reduced amount of gas is released into the liquid.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 2 - PATENT ATTORNEYS

In a ventilation device known from DE-OS 22 61 994, an air hose made of elastic material is provided, connected at one end to an air supply line and closed at the other end, with an unperforated bottom and a top provided with a large number of air outlet openings, whereby the air hose is held at its longitudinal edges by a support member and a membrane under the tension of an air cushion is arranged in the air hose, which forms the lower boundary of an air duct connected to the air supply line. The two hose walls are connected to one another at the two longitudinal edges by a weld seam and each form a loop that encloses one of the two strand-shaped support members. The membrane under the tension of an air cushion is also welded to the two hose walls at its two side edges. The air hose is also supported on both sides by a steel sheet profile that covers the weld seams and prevents them from peeling open. The steel sheet profile is intended to increase the rigidity and weight of the air hose; it can also be provided on the underside of the air hose, with the weight being appropriately dimensioned to be slightly greater than the buoyancy of the hose filled with air. This known ventilation device is structurally complex and therefore expensive.

From DE-PS 507 294 a device for aerating liquids using air jet pipe systems is known, whereby perforated metal or other material air supply pipes are enclosed by rubber sleeves which have fine holes that only open under the pressure of the air introduced into the jet pipe system.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 3 _ PATENT ATTORNEYS

The aim is to achieve fine ventilation and the creation of a valve effect when the air flow is turned off. The rubber sleeves require special effort to support them, namely the entire jet pipe system. In addition, replacing worn and defective rubber sleeves is very time-consuming.

In a gassing device known from DE-PS 34 10 267, a base body is provided which has at least one inlet for the gas. The membrane covers the base body and is attached to it. A device for limiting the stroke of the membrane is also attached to the base body. The inlet for the gas is guided through the base body as a passage opening. The limiting device consists of a connection which is attached to the membrane at one end in the area where the passage opening covers it and which interacts with a counterpart arranged in the area of the passage opening at its other end. Here too, many parts are required to be assembled together, which makes the gassing device more expensive in terms of time and material expenditure. In addition, with this gassing device, the gas also emerges from the essentially horizontal membrane and rises relatively quickly to the liquid level.

The object of the invention is therefore to create a generic gassing device, while avoiding the above-mentioned disadvantages, by means of which a better aeration of the liquid can be achieved with simple production.

This object is essentially achieved according to the invention in that the gas distributor has a base body around which the wall is essentially cylindrical with essentially

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 4 _ PATENT ATTORNEYS

is arranged along a vertically extending central axis and delimits, for example, an annular chamber in the base body, which is connected to at least one gas supply channel and encloses at least one liquid channel that runs essentially vertically through the base body.

The gas thus escapes over the entire cylindrical outer surface of the membrane-like wall in a horizontal direction, so that the residence time of the gas bubbles in the liquid is increased and the aeration effect is thereby improved compared to gas bubbles that escape upwards from an upwardly inclined or horizontal surface. The base body gives the gas distributor the necessary stability, while the at least one liquid channel inside the base body achieves an increased, downward liquid flow. The reason for this phenomenon appears to be that the liquid around the membrane-like cylindrical wall has a higher concentration of gas bubbles than the liquid further inside in the area of the liquid channel. As a result, the specific weight of the liquid around the gas distributor is lower than that of the liquid in the area of the liquid channel, so that the liquid rises around the gas distributor, while a downward flow occurs in the liquid channel of the gas distributor. This leads to increased liquid circulation and thus improved aeration properties of the gas distributor. It was also found that the rising bubble stream expands upwards when the gas flows out over the entire circumference of the wall. This is in contrast to gas distributors in which no liquid channel is formed in the center. In the latter gas distributors, the cross-section of the rising bubble stream decreases upwards.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ c _ PATENT ATTORNEYS

Due to this circumstance, the device according to the invention surprisingly improves the gassing of liquids.

In a particularly advantageous embodiment of the invention, the gas outlet openings are distributed substantially over the entire surface of the wall, preferably evenly, in order to ensure a uniform supply of gas into the liquid.

A particularly simple and cost-effective manufacture and assembly of the invented gassing device is achieved in that the wall consists of a flexible cylindrical piece of hose, which is connected at its two axial ends to the base body, which is preferably also cylindrical.

In a further development of this inventive concept, the at least one liquid channel is delimited by a hose element that leads through the chamber and is attached to the base body. In this case, the base body can have a very simple basic shape.

The hose element is advantageously less flexible than the wall. This means that the wall expands outwards when pressure is applied, while the hose element remains rigid inside the gas distributor and a reduction in the cross-section of the liquid channel is avoided.

However, it is also possible that the at least one liquid channel is formed in one piece, e.g. as a bore in the base body.

Keil&Schaafhausen

- 6 - PATENT ATTORNEYS

Preferably, the at least one liquid channel runs parallel to the cylindrical wall, i.e. vertically.

In a preferred embodiment of the invention, a single liquid channel runs coaxially with the piece of hose forming the wall. This achieves a symmetrical flow path of the downward-directed liquid stream in the middle of the gas distributor.

However, it is also possible that several fluid channels are formed in the base body.

In a further preferred embodiment of the invention, in which the at least one liquid channel is not guided centrally through the base body, the gas supply channel is arranged coaxially to the base body.

According to a further feature of the invention, the effective opening cross-section of the gas outlet openings has a different size in adaptation to the liquid pressure to be overcome by the gas exiting through the gas outlet openings. In order to achieve, for example, a uniform gas outlet over the entire cylindrical membrane surface, the opening cross-section of the gas outlet openings in the bubble wall decreases from bottom to top to the extent that the liquid pressure decreases from bottom to top depending on the vertical height of the bubble.

A uniform gas discharge can also be promoted by having the wall of different thicknesses to adapt to the liquid pressure that has to be overcome by the gas exiting through the gas outlet openings.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

- 7 - PATENT ATTORNEYS

the wall in the lower area is less thick than in the upper area, so that the gas passage through the gas outlet openings in the lower area of the wall is opposed by a lower flow resistance than in the upper area of the wall, so that the total pressure to be overcome by the escaping gas is approximately the same.

The wall can be made of an elastic material, e.g. rubber-elastic material, which bulges outwards under the pressure required for gassing and thus increases the effective area of the gas distributor.

However, it is also possible for the wall to be made of a non-stretchable material, e.g. textile. In this case, the size and shape of the wall are fixed, independent of the pressure, above a minimum gas pressure.

On the other hand, if the textile material allows a certain amount of stretching, it is also possible to combine the properties of an extensible material with those of a non-extensible material. This can be achieved in particular by the wall being made of textile material or having a textile reinforcement insert or overlay.

It is also within the scope of the invention if the gas outlet openings are made into the pre-stressed wall made of expandable material. In this case, the gas outlet openings are closed without pressurizing the chamber, while they only open when the gassing gas is present at a minimum pressure. Within a certain pressure, the opening cross-section of the gas outlet openings is pressure-dependent and can be adjusted accordingly.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

PATENT ATTORNEYS

If a pressure-independent opening cross-section of the gas outlet opening is desired, these are preferably installed in the non-prestressed wall. They then have essentially the same opening cross-section before and during gas exposure, regardless of the pressure.

Another feature of the invention is that the gas outlet openings have an opening cross-section that increases from the inside to the outside, i.e. radially, i.e. they are conical. This has the advantage that when the gas escapes from the wall, any dirt deposits from the gas outlet openings are easily carried along, thus reducing the risk of blockages even in relatively small gas outlet openings. Such gas outlet openings are made, for example, in the form of perforations by pinholes from the outside of the wall.

According to the invention, the gas transport from the gas supply channel to the chamber with the wall takes place through at least one connecting channel that preferably runs radially in the base body, e.g. from the central gas supply channel to the outer surface of the base body.

A uniform pressure load on the entire wall is ensured by the fact that an annular groove is formed on the outer surface of the base body, into which the connecting channel opens and which is covered by the wall.

In a further preferred embodiment of the invention, a tubular, flexible, membrane-like wall element is provided in the upper region of the base body, which

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

- 9 - PATENT ATTORNEYS

is arranged radially inwardly offset from the wall and forms the chamber with it.

The wall element can have a large number of gas outlet openings. This also allows the liquid flowing downwards inside the gas distributor to be ventilated.

For easy attachment of the gas distributor to the gas supply device, the invention provides that the gas supply channel has an internal thread with which the gas distributor can be screwed onto a pipe socket of the gas supply device provided with a corresponding external thread.

The gas supply channel is formed, for example, in a gas supply nozzle provided on the base body.

However, it is also possible for the gas distributor to be pushed onto a pipe socket of the gas supply device using the gas supply nozzle. Such a gas distributor can be easily replaced if it is defective. For safety reasons, the gas supply nozzle can be secured to the pipe socket using a clamp so that even greater pressure loads can be handled.

In another embodiment, the gas distributor has a gas supply nozzle with a bead, which can be inserted into a gas supply opening of the gas supply device. This also allows the gas distributor to be assembled and disassembled relatively easily.

In the gas supply channel and/or the pipe socket and/or the gas supply opening, a valve, e.g. as a flap or

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 10 - PATENT ATTORNEYS

A check valve in the form of a ball valve must be installed, which prevents the liquid from entering the pipe socket or the pipe system of the gas supply device in the event of a pressure drop.

In order to counteract the buoyancy of the gassing device when the chamber is full, the invention further proposes that a ballast weight be arranged in the base body, in particular the chamber. The ballast weight can be designed as a hollow body made of rigid or flexible material, the interior of which is in flow connection with the liquid surrounding the gas distributor and/or can be filled with a liquid such as water, concrete, lead or the like as a ballast weight. However, the ballast weight can also be arranged outside the gas distributor. The base body itself can also be designed as a ballast weight.

Further aims, features, advantages and possible applications of the present invention emerge from the following description of embodiments and the drawing. All described and/or illustrated features form the subject matter of the invention on their own or in any combination, regardless of their summary in the claims or their reference back to them.

Show it:

Fig. 1 is a schematic sectional view of a gas distributor according to a first embodiment of the invention,

Fig. 2 is a sectional view of a gas distributor according to a second embodiment of the invention,

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

- 1 1 - PATENT ATTORNEYS

Fig. 3 is a sectional view of a gas distributor according to a third embodiment of the invention along the line III - III in Fig. 4,

Fig. 4 is a plan view of the gas distributor according to Fig. 3,

Fig. 5 is a sectional view of a gas distributor according to a fourth embodiment of the invention along the line V-V in Fig. 6,

Fig. 6 is a plan view of the gas distributor according to Fig. 5,

Fig. 7 is a sectional view of a gas distributor according to a fifth embodiment of the invention along the line VII - VII in Fig. 8,

Fig. 8 is a plan view of the gas distributor according to Fig. 7,

Fig. 9 is a side view of a gassing device according to the invention showing the attachment to a gas supply device, and

Fig. 10 is a side view of another embodiment of the invention with a different type of attachment to the gas supply device.

A device according to the invention for gassing liquids consists of a gas distributor 1 which is arranged below the liquid level and which can be connected to a gas supply device 2 .

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

- 12 - PATENT ATTORNEYS

The gas distributor 1 shown in Fig. 1 consists of a base body 3 in which a chamber 4 and a gas supply channel 5 are formed. An internal thread is provided in the gas supply channel 5 so that the gas distributor 1 can be screwed onto a pipe socket of the gas supply device 2 provided with an external thread. The base body 3 is cylindrical and has a cylindrical wall 6 made of flexible, membrane-like material in which a large number of gas outlet openings 7 are formed (see Fig. 9 and 10). The wall 6 is attached at its axial ends to the outside of the base body 3, for example with clamps 8. If air is introduced into the chamber 4 through the gas supply channel 5, the wall 6 expands, as shown by the dashed line. A liquid channel 9 extends essentially vertically through the base body 3 and is formed by a hose element 10 connected to the base body 3 at its upper and lower ends. The hose element 10 can be made of solid or flexible material. The flexibility of the hose element 10 is less than the flexibility of the wall 6, so that the wall 6 expands outwards when pressure is applied, while the hose element 10 remains rigid. When the gas distributor 1 is pressurized, air escapes through the gas outlet openings 7 in the wall 6 essentially in a horizontal direction. This results in a relatively long residence time of the gas bubbles in the liquid. During operation, a downward-directed liquid flow F is created in the liquid channel 9, as indicated by the downward-directed arrow in Fig. 1. The liquid flow F seems to be due to the fact that the liquid around the membrane-like cylindrical wall 6 has a higher concentration of gas bubbles than the liquid inside the liquid channel 9. This means that the specific

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

₁ &ogr; PATENT ATTORNEYS

Weight of the gas-laden liquid around the gas distributor 1 is on average less than that of the liquid in the inner liquid channel 9. This leads to the liquid rising around the gas distributor 1, while the liquid in the middle of the gas distributor 1 flows from top to bottom. This results in increased circulation and therefore better aeration of the liquid. It has also been found that the rising bubble stream expands upwards when the gas flows out over the entire circumference of the jacket 6. This phenomenon is in contrast to gas distributors in which no liquid channel is formed in the middle. In such gas distributors, the area of the rising gas bubbles decreases towards the top. This also means that better liquid aeration is achieved with the device according to the invention.

The embodiment according to Fig. 2 differs from that shown in Fig. 1 essentially in that several liquid channels 9 are formed in the base body 3. The gas supply channel 5 in the embodiment according to Fig. 2 is also formed coaxially with the base body 3 and leads directly into the middle of the chamber 4. A downward liquid flow F is caused in each of the liquid channels 9.

In the embodiment according to Figs. 3 and 4, the wall 6 is essentially directly on the outside of the base body 3 when the gas distributor 1 is not pressurized. The chamber volume is then practically zero. However, a small recess can also be provided for the chamber 4. If the wall 6 is expanded outwards when pressure is applied, the chamber 4 increases in size. The gas

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ -&igr; 4 _ PATENT ATTORNEYS

supply channel 5 is arranged coaxially with the base body 3 and is connected to the chamber 4 via a plurality of radial connecting channels 11. The connecting channels 11 are arranged in ribs 12 of the base body 3, which form a plurality of liquid channels 9 in an upper section 3' of the base body 3. The air L enters the gas supply channel 5 from below, as shown by the arrow in Fig. 3, then exits radially through the connecting channels 11 to the outside, as shown by the arrows in Fig. 4, and then enters the chamber 4, where the wall 6 expands outwards due to the pressure and the air exits through the gas outlet openings 7. Here too, a downward liquid flow F is caused which, as shown by the arrow in Fig. 3, flows through the plurality of liquid channels 9.

The embodiment shown in Figs. 5 and 6 is similar to the embodiment according to Figs. 3 and 4. In the embodiment according to Figs. 5 and 6, however, an outer circumferential annular groove 13 covered by the wall 6 is formed in the base body 3, into which the connecting channels 11 open. The groove 13 ensures that the air or gas is guided over the entire circumference of the body 3 into the chamber 4 and to the inner surface of the wall 6. In contrast, in the embodiment according to Figs. 3 and 4, the air or gas is introduced into the chamber 4 at only two points, at least at the beginning, which correspond to the outer ends of the connecting channels 11. In this embodiment, the wall 6 should therefore not have any gas outlet openings 7 in the area around the openings of the connecting channels 11 into the chamber 4. This achieves good gas distribution in the chamber 4.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 15 _ PATENT ATTORNEYS

While in Figs. 3 to 6 the upper region 3' of the base body 3 consists of rigid material, in the embodiment according to Figs. 7 and 8 this rigid section ³¹ of the base body 3 is replaced by a tubular, flexible, membrane-like wall element 14 which has a large number of gas passage openings. The lower end of the wall element 14 is attached to the base body 3, while the upper end of the wall element 14 is held, for example, via the clamps 8 to a clamping element 15. The clamping element 15 can be a section of the base body 3 or can be connected to it. If gas is now introduced into the chamber 4 via the connecting channels 11, the wall 6 will initially expand outwards according to the dashed line. The wall element 14 will then expand inwards, as shown by the dash-dotted line. By widening the wall element 14 inwards into the liquid channel 9, the downward liquid flow in the liquid channel 9 is additionally increased. In the embodiment according to Figs. 7 and 8, the groove 13 can also be formed in the base body 3.

The embodiments according to Figs. 9 and 10 differ from the above-mentioned essentially by a different type of fastening of the gas distributor 1 to the gas supply device 2. The gas supply device 2 has a pipeline 16, from which one or more pipe sockets 17 branch off to a gas supply opening 18.

In the embodiment according to Fig. 9, a gas supply nozzle 19 is provided on the gas distributor 1, in which the gas supply channel 5 is formed. The gas supply nozzle 19 is connected via the

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

_ 16 _ PATENT ATTORNEYS

Pipe socket 17 can be put over and secured using a clamp 20. The gas distributor 1 is thus securely fastened to the gas supply device 2. In the pipe socket 17, in front of the opening of the gas supply channel 5, there is a check valve 21 designed as a ball valve, which opens when subjected to gas pressure and closes when the pressure drops, so that no liquid can get into the gas distributor 1 and the gas supply device 2 via the gas outlet openings 7.

The embodiment according to Fig. 10 differs from that shown in Fig. 9 essentially in that the gas supply nozzle 19 is designed as a bead 22 which can be snapped into the gas supply opening 18 of the pipe 16.

Also in the embodiments according to Figs. 9 and 10, the direction of the liquid flow F is made clear by the downward-pointing arrows.

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN

PATENT ATTORNEYS

List of reference symbols:

1 Gas distributor 2 Gas supply device 3 Base body 3' upper section 4 chamber 5 Gas supply channel 6 Wall 7 Gas outlet openings 8th Brackets 9 Fluid channel 10 Hose element 1 1 Connecting channels 12 Ribs 13 Groove 14 Wall element 15 Clamping element 16 Pipeline 1 7 Pipe socket 18 Gas supply opening 19 Gas supply nozzles 20 clamp 21 check valve 22 bead 23 inner thread F Fluid flow L Airflow

Claims (31)

Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN - 1 - PATENT ATTORNEYS Protection claims: 1. Device for gassing liquids, in particular for aerating waste water, by means of a gas distributor (1) which can be arranged below the liquid level and connected to a gas supply device (2), which has at least one membrane-like wall (6) made of flexible material with a plurality of gas outlet openings (7), characterized in that the gas distributor (1) has a base body (3), around which the wall (6) is arranged essentially cylindrically with an essentially vertically running central axis and delimits a chamber (4) in the base body (3), which is connected to at least one gas supply channel (5) and encloses at least one liquid channel (9) leading essentially vertically through the base body (3). 2. Device according to claim 1, characterized in that the gas outlet openings (7) are distributed substantially over the entire wall (6). 3. Device according to claim 1 or 2, characterized in that the wall (6) consists of a flexible cylindrical piece of hose which is connected at its two axial ends to the preferably also cylindrical base body (3). 4. Device according to one of claims 1 to 3, characterized in that the at least one liquid channel (9) is delimited by a hose element (10) leading through the chamber (4) and fastened to the base body (3). Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN _ 2 - PATENT ATTORNEYS 5. Device according to claim 4, characterized in that the hose element (10) has a lower flexibility than the wall (6). 6. Device according to one of claims 1 to 3, characterized in that the at least one liquid channel (9) is formed in one piece, e.g. as a bore, in the base body (3). 7. Device according to one of claims 1 to 6, characterized in that the at least one liquid channel (9) runs parallel to the cylindrical wall (6). 8. Device according to one of claims 1 to 7, characterized in that a single liquid channel (9) runs coaxially with the hose piece forming the wall (6). 9. Device according to one of claims 1 to 7, characterized in that several liquid channels (9) are formed in the base body (3). 10. Device according to one of claims 1 to 7 and 9, in which the at least one liquid channel (9) is not guided centrally through the base body (3), characterized in that the gas supply channel (5) is arranged coaxially with the base body (3). 11. Device according to one of claims 1 to 10, characterized in that the effective opening cross-section of the gas outlet openings (7) has a different size in adaptation to the liquid pressure to be overcome by the gas exiting through the gas outlet openings (7). KEIL&SCHAAFHAUSEN - 3 - PATENT ATTORNEYS 12. Device according to one of claims 1 to 11, characterized in that the wall (6) has a different thickness in adaptation to the liquid pressure to be overcome by the gas exiting through the gas outlet openings (7). 13. Device according to one of claims 1 to 12, characterized in that the wall (6) consists of an expandable, for example rubber-elastic material. 14. Device according to one of claims 1 to 12, characterized in that the wall (6) consists of a non-stretchable material. 15. Device according to one of claims 1 to 14, characterized in that the wall (6) consists of a textile material or has a textile reinforcing insert or overlay. 16. Device according to one of claims 1 to 15, characterized in that the gas outlet openings (7) are introduced into the prestressed wall (6) made of expandable material. 17. Device according to one of claims 1 to 15, characterized in that the gas outlet openings (7) are introduced into the non-prestressed wall (6). 18. Device according to one of claims 1 to 17, characterized in that the gas outlet openings (7) have an opening cross-section that increases from the inside to the outside. 19. Device according to one of claims 1 to 18, characterized in that in the base body (3) at least one Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN - 4 - PATENT ATTORNEYS connection channel (11) is formed, which the gas supply channel (5) with the chamber (4). 20. Device according to claim 19, characterized in that the at least one connecting channel (11) runs radially in the base body (3), e.g. from the central gas supply channel (5) to the outer surface of the base body (3). 21. Device according to claim 19 or 20, characterized in that an annular groove (13) is formed on the outer surface of the base body (3), into which the at least one connecting channel (11) opens and which is surrounded by the wall (6) is covered. 22. Device according to one of claims 1 to 21, characterized in that in the upper region of the base body (3) a tubular, flexible, membrane-like wall element (14) is provided, which is arranged radially inwardly offset from the wall (6) and forms the chamber (4) with it. 23. Device according to claim 22, characterized in that a plurality of gas outlet openings are formed in the wall element (14). 24. Device according to one of claims 1 to 23, characterized in that the gas supply channel (5) has an internal thread (23). 25. Device according to one of claims 1 to 24, characterized in that the gas supply channel (5) is formed in a gas supply nozzle (19) provided on the base body (3). Sch 50 G 4 CIP KEIL&SCHAAFHAUSEN _ &igr;- PATENT ATTORNEYS 26. Device according to one of claims 1 to 25, characterized in that the gas distributor (1) is slipped onto a pipe socket (17) of the gas supply device (2) by means of the gas supply socket (19). 27. Device according to one of claims 1 to 25, characterized in that the gas distributor (1) has a gas supply nozzle (19) with a bead (22) which can be snapped into a gas supply opening (18) of the gas supply device (2). 28. Device according to one of claims 1 to 27, characterized in that a check valve (21) is arranged in the gas supply channel (5) and/or the pipe socket (17) and/or the gas supply opening (18) or the vicinity thereof. 29. Device according to one of claims 1 to 28, characterized in that a ballast weight is arranged in the base body (3). 30. Device according to claim 29, characterized in that the ballast weight is designed as a hollow body made of rigid or flexible material, the interior of which is in flow connection with the liquid surrounding the gas distributor (1) and/or can be filled with a liquid such as water, concrete, lead or the like. 31. Device according to one of claims 1 to 30, characterized in that the base body (3) is designed as a ballast weight.