EP4058699A1 - Float valve, compressed-air system having a float valve, and drier for a compressed-air system having a float valve - Google Patents

Abstract

The invention relates to a float valve (10), in particular for draining condensate in a medical compressed-air system, comprising: a float (12); a valve seat (16), which defines a valve opening (18a, 18b; 18) having a valve opening cross-sectional area qA; and a closure element (14) for opening and closing the valve opening cross-sectional area qA of the valve opening (18a, 18b; 18). The closure element (14) can be controlled by means of the float (12) between a completely open position X and a completely closed position Y. The closure element (14) is elastic and is part of a partial opening mechanism, which is designed to successively open the valve opening cross-sectional area qA of the valve opening (18a, 18b; 18) between the completely closed position Y and the completely open position X as a result of the elasticity of the closure element (14).

Description

Float valve, compressed air system with a float valve and dryer for a compressed air system with one

Float valve

BACKGROUND OF THE INVENTION

1. Field of the invention

The invention relates to a float valve, a compressed air system with a Schwimmerven valve and a dryer for a compressed air system with a float valve.

2. Description of the prior art

Float valves are often used to drain liquids, such as condensate from a compressed air system. The float valve usually has a valve seat that forms a valve opening. To switch the valve, a movable closure element is also often provided, which works together with the valve seat and releases the valve opening or closes it in a sealing manner. For this purpose, a float controls the closure element via various types of control mechanisms. The float can be arranged in a housing together with the other valve components. However, it can also be arranged outside of such a housing in a collecting container or the like, such as in the case of a toilet flush box, and act on the closure element from its position there via a corresponding control mechanism. As a result of the accumulation of liquid, a buoyancy force acts on the float, which is available to the control mechanism in order to lift the closure element off the valve seat. In compressed air systems, however, it is the case that a relatively high opening force is required to open the closure element. This is because the overpressure in the compressed air system ensures a mostly not insignificant pressure difference on the closure element or in the area of the valve opening of the closure element. As a result, very large swimmers would have to be provided that generate sufficient buoyancy.

So far, therefore, in the prior art for such a compressed air system, especially in the medical field and especially in the dental field, control mechanisms are used which, for example, strongly translate the buoyancy force with a lever mechanism in order to exert the necessary opening force on the closure element. Such float valves, however, have the disadvantage that many components are required who must be precisely matched to one another. In addition, the float needs a long movement path, which, depending on the installation situation in the compressed air system, cannot be made available.

Another solution in the prior art comprises a control mechanism with a pneumatic pilot control, in which a small pilot valve is first opened in order to use compressed air from the compressed air system to control the actual closure element.

In addition to the complex production of such a float valve, this pilot control has the disadvantage that the small pilot valve is prone to clogging by small particles, which means that the float valve opens permanently or does not open at all, depending on the location of the particle inclusion.

SUMMARY OF THE INVENTION

The object of the invention is therefore to provide a float valve which takes into account the above considerations relating to the prior art and in particular has a simpler structure than the float valves known in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

This object is achieved by a float valve, in particular for draining condensate in a medical compressed air system, comprising: a) a float; b) a valve seat which defines a valve opening with a valve opening cross-sectional area q _A; and c) a closure element for releasing and closing the valve opening cross-sectional area q _{A of} the valve opening, the closure element being controllable between a fully released position X and a fully closed position Y by means of the float. According to the invention, the closure element is elastic and part of a partial opening mechanism which is set up to _{gradually release the valve opening cross-sectional area q A of} the valve opening between the fully closed position Y and the fully released position X due to the elasticity of the closure element.

The inventors have recognized that the elasticity of the closure element and the partial opening mechanism make it possible for the entire valve opening cross-sectional area q _A not to be suddenly released when the valve opening is released. _{Instead, the valve opening cross-sectional area q A of} the valve opening is successively, ie gradually, released by the elasticity of the closure element and by the partial opening mechanism. The elastic closure element is thus lifted off the valve seat in a "peeling" movement.

This has the advantage that the opening forces that have to be applied to release the valve opening are reduced compared to the immediate release of the entire valve opening cross-sectional area q _A.

Since the opening force required to open the valve opening after

F = Dr * A be determined primarily by the pressure difference on the closure element and the area to be opened, a smaller area to be opened is advantageous in order to open the closure element with low opening forces despite a high pressure difference.

In the case of a compressed air system in particular, the pressure difference can essentially result from the difference between the pressure that is present in the flow line, which is arranged downstream of the closure element, and the pressure that is produced directly by the liquid to be discharged, for example condensate, usually acts on the locking element from above. This is the case with medical compressed air systems, in which the float valve must also comply with the strict hygiene regulations (e.g. lower number of particles and lower oil content in the compressed air), so that complex mechanics that may require lubricant, to forbid.

In addition, in most cases the weight of the float, which can be made of a foamed material, for example a particle foam, and the closing element counteract the opening of the closing element, since the float and the closing element are in the closed state of the float valve As a rule, they are oriented essentially vertically and are opened with at least one vertical opening direction component.

In the closed state of the valve opening, the pressure in the flow line downstream of the closure element corresponds essentially to the ambient pressure. The pressure acting directly on the closure element from the liquid to be drained comprises, on the one hand, the hydraulic pressure of the liquid to be drained, which is determined by the height of the water column prevailing at the closure element. On the other hand, the pressure above the liquid to be drained also acts. In a conventional compressed air system, this pressure is about 5 bar to about 10 bar, as a rule, significantly above the ambient pressure, since the area above the liquid level is usually connected directly or indirectly to a pressure line of the pressure system. The explained pressure difference, taking into account the relevant areas of the closure element, results in the closure force that acts on the closure element when the float valve is closed. The valve opening force is in turn the force that must be exerted on the closure element in order to overcome the closure force explained.

If, as provided by the invention _{, only a part of the valve opening cross-sectional area q A is} opened at one moment, only part of the total valve opening force has to be exerted on the closure element in order to release this part of the valve opening cross-sectional area q _A. As soon as a sub-area of the valve opening cross-sectional area which is smaller in relation to the total valve opening cross-sectional area has been released, the liquid to be drained already flows off over this sub-area of the valve opening cross-sectional area.

The partial pressure equalization resulting therefrom over the opened partial area of the valve opening can reduce the pressure difference, as a result of which the opening force required to release the remaining cross-sectional area of the valve opening is further reduced.

In pressureless systems, essentially only the hydraulic pressure of the liquid to be drained, for example condensate, acts on the closure element. In addition, as already described, the weight of the float and the closure element counteract the opening of the closure element. The valve opening forces to be applied to open the closure element are therefore lower in pressureless systems than in pressurized systems. However, the float valve according to the invention works for both systems.

The lower opening forces for opening the closure element also make it possible to enlarge the valve opening cross-sectional area q _A using a conventional float known from the prior art. A larger cross-sectional area q _{A of the} valve opening has the advantage that it is less sensitive to particles that may possibly penetrate the valve. Elastic is generally to be understood as the property of a material that allows deformations of the material, for example bending or curvature, by applying forces, for example by pushing or pulling, and essentially returning to its original state after the forces have ceased to take.

For the present invention, the elasticity of the closure element enables, above all, that during the opening of the closure element, the closure element can be deformed in such a way that areas of the closure element are movable differently from the other areas of the closure element. In particular, the elasticity should be selected such that an area of the closure element can already be lifted off the valve seat in order to open a partial area of the valve cross-sectional area, while another area closes another part of the valve cross-sectional area. A region of the closure element can preferably be moved in a plane that differs from the other regions of the closure element. However, it is also conceivable to perform a superimposed movement of the area of the closure element in several planes.

The elastic closure element can preferably be made from an elastomer. However, it is also conceivable that the elastic closure element is made of a different material such as a thermoplastic or a thin sheet of spring steel.

The closure element can preferably be connected directly to the float. The closure element can preferably be connected to the float in a materially bonded manner, for example as an elastic layer vulcanized or glued to the float. Alternatively, the closure element can also be connected to the float in a force-locking or material-locking manner by means of at least one holding element attached to the float or to a further element connected in between. The closure element can thus also interact directly with the float in order to form the partial opening mechanism.

Alternatively, the closure element can be indirectly connected to the float via further components and can interact with the float. Would be conceivable For example, a resilient sheet-like element to which the closure element is taken fastened. The swimmer's vibrations can be better cushioned by resilient sheet-like elements.

A completely released position X is to be understood as a position of the closure element in which the closure element represents essentially no flow resistance, or at least less in comparison to the further flow resistances, for the liquid to be drained off.

A completely closed position Y is to be understood as a position of the closure element in which the valve opening is essentially sealed off by means of the closure element, so that essentially no medium exchange takes place between the environment and the medium to be released.

Under successive releasing the valve opening cross-sectional area q _A of the valve opening is a becomes larger with the movement of the closing element between the fully closed-end position Y and the fully released position X partial cross-section of the valve opening cross-sectional area q _A of the valve opening understood while another portion of cross section of the valve opening cross-sectional area q _A still is not released.

The valve opening _{cross-sectional area q A} can preferably have two partial cross-sections, a first released partial cross-section and a second non-released partial cross-section. When the closure element is moved between the fully closed position Y and the fully released position X, the first part becomes larger in cross section while the second part cross section becomes smaller.

Further aspects of the invention emerge from the subclaims explained below.

The elastic closure element can preferably have a band for releasing and closing the valve opening cross-sectional area q _{A of} the valve opening, at least in some areas, the band being set up to provide a completely closed senen position Y and the fully released position X to be removed from the valve opening by peeling, in order to _{gradually release the valve opening cross-sectional area q A of} the valve opening by the peeling removal.

Here, the above-mentioned partial opening mechanism comprises the band and the band is at the same time the closure element. For this purpose, the tape can be laid twice over the valve opening like a loop, whereby when the upper part of the tape lying in the loop is pulled, the peeling-off manner of removing the tape to successively release the valve opening cross-sectional area q _{A of} the valve opening results. Preferably, in the fully closed position Y and in the fully released position X, the band is arranged essentially concentrically to the valve opening. Alternatively, however, the band in the fully closed position Y and in the fully released position X can also be arranged eccentrically to the valve opening. It would also be conceivable to arrange the band in such a way that in the completely closed position Y the band is arranged essentially concentrically to the valve opening and in the completely released position X eccentrically to the valve opening, or vice versa.

The band can preferably be constructed in such a way that the band has resilient properties in order to cushion the swimmer's vibrations even without the aid of additional damping elements. This enables the float valve to open and close gently. This in turn reduces noise and mechanical loads in the float valve.

Furthermore, the resilient properties of the band at least partially compensate for the weight of the swimmer. This further reduces the valve opening force required to open the closure element. This means that the float valve can also be opened at lower liquid levels or smaller floats. The band can have a band thickness that is equal to or greater than a diameter of the valve opening in order to cover and close at least the entire valve opening in the completely closed position Y.

Another advantage of the band is that the band can compensate for possible tolerances between the valve seat and the float. Exact guidance of the float and the closure element can thus be dispensed with. This further simplifies the construction of the float valve.

A holding means can preferably be provided on the float and / or on the valve seat, by means of which the strap can be fastened to the float and / or to the valve seat.

As a result, the band can be positioned more precisely on the valve seat, in particular when the closure element is closed, in order to improve the closing function and thus the tightness of the closure element on the valve seat. A corresponding counter-holding means can be molded onto the band. The holding means can be arranged concentrically to the valve opening, for example in the middle of a circular valve opening. In this case, the holding means can be connected to the material of the valve seat by means of a web or by means of several webs.

Alternatively, the holding means can be arranged eccentrically to the valve opening, for example at a distance of less than about 5 cm from the center of the valve opening. In this context, the term “on the valve seat” also includes the immediate vicinity of the valve seat, for example at a distance of approximately 3 cm from the outer edge of the valve opening.

The holding means can also only be provided on the float. In this case, the area of the belt facing the valve seat is free and can therefore be moved independently of the valve seat.

The holding means can preferably form a form-fitting connection to the band, for example as an annular element which receives the band in a form-fitting manner. The However, the holding element can also be a holding means that does not require an additional component, but is formed by the band, the float or the valve seat, or a combination of these three components. For example, the band can be fused onto the valve seat and / or onto the float and thus produce a material connection to the valve seat and / or to the float.

Preferably the band is a closed band.

The band can preferably have a uniform cross section. However, a non-uniform cross section is also conceivable. The non-uniformity can consist, for example, in the fact that the band has stiffening areas or areas for fastening the band which differ from the other areas with regard to the cross section. Such stiffening areas or areas for fastening the tape can in particular be provided in the vicinity of the float and / or in the vicinity of the valve seat.

Overall, it should be noted with regard to the band-shaped closure element that the band-shaped closure element can be set up to act as a spring due to its shape, its material properties and / or its fastening. For example, this can make the float valve less sensitive to fluctuations in the liquid level. In this way, however, it can also be ensured that from a predetermined lower position of the float the float valve remains closed in any case if the band has such a spring effect that from this position onwards it presses against the valve seat.

In one embodiment, the closure element can be positioned eccentrically to the valve opening at least in the fully closed position Y and can be attached to the float unevenly in such a way that when controlling the closure element between the fully closed position Y and the fully released position X, the closure element is peeled off is removed from the valve opening and the valve opening cross-sectional area q _{A of} the valve opening can gradually be released by the peeling removal. In this embodiment, the above-mentioned partial opening mechanism is decisively formed by the uneven manner of fastening the elastic closure element on the float. Uneven fastening of the elastic closure element on the float is a regional fastening of the elastic closure element on the float, the remaining area of the elastic closure element not being fastened on the float.

As a result, the opening force of the closure element, which is brought about by the buoyant force of the liquid to be drained on the float, is only exerted on the fastened areas of the closure element. The remaining area experiences no, or at least less, opening forces than the secured area.

Thus, at the beginning of the opening process, only the portion of the valve opening cross-sectional area that is closed by the fastened area of the closure element in the closed state of the closure element is released. The rest of the unfastened area initially remains closed and is only released in the course of the further opening process. As a result, the valve opening cross-sectional area q _{A is} opened successively according to the invention.

The eccentric positioning of the closure element in relation to the valve opening further reduces the necessary opening force.

The fastening can also be present in several areas of the closure element.

The closure element can preferably be attached to the float in a force-locking manner, for example by means of a press fit, or in a form-locking manner, for example by gluing or melting. Furthermore, the closure element can be attached indirectly, that is not directly, or directly to the float. In one embodiment, the valve opening has several cross-sectional areas of different sizes, the closing element being peelable from the valve opening in a direction in which the closing element can first be peeled off from the smallest cross-sectional area of the valve opening. The peeling off of the closure element at the smallest cross-sectional area initially enables the liquid to be drained to flow out and in this case requires a low valve opening force. The pressure equalization described at the beginning, which is brought about by the liquid flowing out through the released partial cross-section of the valve opening cross-sectional area q _A , can reduce the valve opening force for releasing the larger partial cross-section of the valve opening cross-sectional area q _A.

Cross-sectional areas of different sizes are initially to be understood as meaning areas with different cross-sectional areas. The presence of different cross-sectional areas per se is defined by the fact that cross-sectional areas are meant that are geometrically non-uniform and thus cannot be described as a unit with customary geometrical shapes.

Such cross-sectional areas of different sizes can be designed, for example, as a keyhole shape.

The cross-sectional area of the valve opening will preferably have a circular shape. However, other geometric shapes of the valve opening are also conceivable, for example polygonal or elliptical shapes. Furthermore, the valve opening can also have geometrically atypical shapes, which for example have a profile such that the opening force of the closing element enables the lowest force profile over the entire opening path of the closing _{element when the valve opening cross-sectional area q A of the valve opening is gradually released.} In particular, starting from a first opening point along a peeling direction along which the valve opening cross-sectional area is exposed, the cross-sectional shape can at least in a first sub-area widen less than a comparable circular cross-section of a circular valve opening. In one embodiment, the float valve has several valve openings and the valve openings can be closed and released by a common closure element. The provision of a plurality of valve openings has the advantage that redundancy is provided even if one opening of the plurality of valve openings is blocked, for example due to particles. This means that the likelihood of failure of the float valve is lower than with a version with only one valve opening. In float valves from the prior art, several closure elements are necessary for this in order to have a closure element for each valve opening. According to the invention, however, all closure elements can be closed and released by means of a closure element in order to make the construction of the float valve simpler despite several valve openings. Furthermore, by successively releasing the valve opening cross-sectional area q _{A of} the individual valve openings, the valve opening force required to open several valve openings can not be increased compared to opening a single valve opening. This can be achieved, for example, by a linear arrangement of the individual valve openings that are opened in series one after the other.

The float preferably controls the closure element directly without the aid of a pilot valve.

Because of the lower required opening forces achieved by the invention, pilot controls, as in the prior art float valves mentioned at the beginning, can be dispensed with. The closure element can thus be controlled exclusively by means of the float and the disadvantages associated with a pilot control are avoided.

The invention also relates to a compressed air system, in particular for providing compressed air for the compressed air operation of dental devices, with one of the preceding float valves according to the invention.

The invention also relates to a dryer for a compressed air system with one of the preceding float valves according to the invention. The float valve according to the invention can also be used in other applications in which an outlet is to be closed twice and opened twice. For example, this applies to a rinsing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. In these show:

Figure 1 is a perspective sectional view of an inventive Schwimmerven tils in a fully closed position Y according to a first Ausfüh approximately example;

FIG. 2 shows a schematic representation of the float valve from FIG. 1 in the completely closed position Y;

FIG. 3 shows a schematic representation of the float valve from FIGS. 1 and 2 in a completely released position X;

Figure 4 is a centerline perspective sectional view of a float valve with an advantageously shaped valve opening; FIG. 5 is a perspective center line sectional view of a float valve with an otherwise configured valve opening shape;

FIG. 6 shows a float valve according to the invention in the completely closed position Y according to a second exemplary embodiment;

FIG. 7 shows a float valve according to the invention in the completely released position X according to the second exemplary embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a float valve 10 according to the invention for draining liquids according to a first exemplary embodiment with a float 12, which can move along a guide rod 13, which can only be seen with difficulty in FIG with the float 12 connected elastic closure element, which is designed according to the first embodiment as a band 14 but can also have other For men in detail.

In order to guide the float 12 when it is moving, the float 12 has a guide device 7 for receiving the guide rod 13.

Arranged in FIG. 1 below the belt 14, the float valve 10 shown here has a valve seat 16, to which a drain connection 4 is connected. In the valve seat, two valve openings 18a, 18b are formed here, which together define _{a valve opening cross-sectional area q A.} However, only one valve opening 18 or several valve seats can also be provided.

The drain connection 4 comprises a circumferential groove 6 for receiving a seal 8 in order to seal the drain connection 4, for example, against a dryer housing 3 of a compressed air system, shown only in dashed lines in FIG. The liquid to be drained can be drained off via the drain channel 9 formed in the drain connector 4, for example into a drain reservoir or a sewer system.

The drainage connection 4 can, however, also be part of a housing (not shown in FIG. 1) for collecting the liquid to be drained.

According to the first exemplary embodiment, the closure element is designed as a closed band 14, which is fastened to the float 12 or to the valve seat 16 via holding means 24, 26 fastened to the float 12 and to the valve seat 16.

The holding means 24, 26 are received by corresponding holding means, which are integrally formed on the band 14. Alternatively, the band 14 can also be stretched around the holding means 24, 26 without holding element receptacles 20, 22 and thus likewise fixed.

Furthermore, a variant is also possible in which the holding means 26 located on the valve seat 16 and the associated holding means receptacle 22 are not present. Correspondingly, the band 14 then runs through the valve seat 16 almost straight. The float valve 10 and its function are explained in more detail with reference to the schematic FIGS.

The float valve 10 shown in FIGS. 2 and 3 drains liquid FL from an atmosphere A into an atmosphere B. In the atmosphere B there is essentially ambient pressure. There is overpressure in atmosphere A when the float valve 10 is used on a compressed air system. Ambient pressure can also prevail in atmosphere A if the float valve 10 is not used on a compressed air system.

The valve seat 16, which defines the two valve openings 18a, 18b with a valve opening cross-sectional area q _A , is formed in a separating material 15. As can be seen from FIG. 1, the separating material 15 can be an end cover on the outlet connection 4. The separating material 15 can, however, also be a wall of a valve housing which defines a hollow space in which the float 12 and the band 14 are arranged. The cavity can serve to collect the liquid to be drained. As can be seen in FIGS. 2 and 3, the two valve openings 18a, 18b can have different valve opening cross-sectional areas.

The band 14 is shown in Figure 2 in the completely closed position Y, in which the band 14 rests on the valve seat 16 and thus _{closes the entire valve opening cross-sectional area q A of} the valve openings 18a, 18b. In the position Y, the belt 14 prevents, at least with regard to liquid FL, an exchange of medium between atmosphere A and atmosphere B.

In contrast to the illustration in FIG. 1, the float valve 10 according to FIGS. 2 and 3 has guide elements 28 which are still in contact with the float 12 and which serve to guide the band 14 when it moves and in a looped form towards the valve seat 16 lay. The guide elements 28 can, for example, only be round bars aligned transversely to the belt 14 (filled circle in FIGS. 2 and 3) be. However, as can be seen from the figures, the guide elements 28 can also provide the band 14 with an external shape over an extended area.

In the example shown here, the guide elements 28 are each connected to the float 12 via a support structure 29 so that they move with the float in order to avoid greater friction between the belt 14 and the guide elements 28.

In addition, the support structure 29 carries a hold-down device 31 which is arranged within the area enclosed by the band 14.

In FIG. 2 there is only a low liquid level of the liquid FL to be drained in atmosphere A, which is why no hydraulic lifting forces act on float 12 which would exert a vertically upward force on float 12.

Due to the weight of the float 12 and the band 14 and the lack of hydraulic buoyancy, which would counteract the two weight forces of the float 12 and the band 14, the band 14 remains in this position Y which closes the valve seat 16.

The hold-down device 31, which, in contrast to the band 14, is connected to the float 12 in a dimensionally stable manner via the support structure 29, additionally holds the band 14 down in this position Y, i.e. presses it against the valve seat 16. As a result, an even more secure closure is guaranteed, the use of a hold-down device 31 not being absolutely necessary. A further alternative or additional improvement of the closure can be effected in that the valve seat 16 is designed, for example, slightly sloping towards the outside.

In FIG. 3, on the other hand, the float valve 10 is in the completely open position X. This is caused by the fact that, compared to FIG. 2, the liquid FL has accumulated at a higher liquid level.

The increased liquid level in turn generates a vertically upward buoyancy force on the float 12. As soon as this is greater than the valve opening force, ie before All the downward force from the pressure difference between atmosphere A and Atmo sphere B and the weight of the float 12 and the belt 14, the swimmer 12 is moved vertically upwards. As a result, the float 12 pulls on the upper part of the band 14. In addition, the hold-down device 31 is lifted off the band 14 so that the band 14 is given back its own freedom of movement.

Since the tape 14 is laid twice over the valve seat in a loop, the tape 14 is automatically removed from the valve seat in a peeling manner by pulling the part of the tape 14 lying above in the loop. As a result, the valve openings 18a, 18b are gradually released both internally and one after the other, whereby the valve opening _{cross-sectional area q A is also} gradually released, so that the liquid is gradually drained off with less resistance in the float valve 10.

Due to the partial pressure equalization that also occurs between the two atmospheres A and B, the pressure difference is reduced, so that the valve opening force is also reduced. Accordingly, a buoyancy force that becomes smaller, for example due to the drop in the liquid level, is sufficient to open the float valve 10 further and / or to keep it open.

The band 14 is in the completely released position X shown in FIG. 3 when the entire valve opening cross-sectional area q _{A of} the respective valve openings 18a, 18b is completely open. In FIGS. 4 and 5, different shapes of a valve opening 18 are shown here using the example of the band 14 as a closure element, which can be provided instead of or for the individual valve openings 18a, 18b.

Thus, FIG. 4 shows a valve opening 18, the cross-sectional shape of which corresponds approximately to an approximately rounded keyhole. It can be seen here that the keyhole is oriented in such a way that, in the valve opening direction 99, a wider main opening area follows a narrower extension area.

FIG. 5 shows a variant in which the cross-sectional shape is a rounded triangle which, starting from a corner, widens in the valve opening direction 99. The decisive factor for the two shown cross-sectional shapes of a valve opening 18, which are advantageous compared to a conventional round cross-sectional shape, is that a region that is as narrow as possible transversely to the valve opening direction 99 lies on the side with respect to the valve opening direction 99 on the side from which the band 14 or the closure element starts from the valve. tilsitz is peeled off. As a result, the valve opening cross-sectional area that is opened can increase to the extent that the valve opening force decreases due to the pressure equalization.

Figures 6 and 7 show a float valve 10 according to the invention according to a further embodiment with a float 12 and an elastic closure element 14 connected to the float 12 for draining liquids from an atmosphere A into an atmosphere B.

Structurally or functionally similar components are provided with the same reference characters as in the above exemplary embodiments.

Like the previous exemplary embodiments, the float valve 10 also comprises a valve seat 16 which is formed on a separating material 15 and defines _{a valve opening 18 with a valve opening cross-sectional area q A.}

In contrast to the above exemplary embodiments, the closure element is not designed in the form of a strip, but rather as a geometrically simple element, for example as an essentially round disk 14, which rests on the valve seat 16. The disk 14 is at least partially received in a recess 33 at the lower end of the float 12 in such a way that the float 12 pulls the disk 14 with it when it moves upward. For this purpose, the disk 14 has an integrally formed billet 20 as a holding means receptacle, which is clipped into a hole 24 as a holding means on the bottom of the recess 33. The stick 20 is arranged on a first section 34 of the disc 14 in such a way that it lies eccentrically from the center of the valve seat 16, whereby the effective axis 95 of the buoyancy force of the float 12 does not coincide with the effective axis 97 of a force, which keeps the float valve 10 on the valve seat 16 closed. The easiest way to achieve this is that the stick 20 and the valve seat 16 are parallel to each other, the positioning of the disc 14 over the valve seat via a housing 17 in which the float 12 is guided. At a section 36 of the disk 14 opposite with respect to the valve seat 16, the latter is shown here unattached, although an attachment would also be conceivable. It is crucial that, due to the elasticity of the disk 14, the section 34 is movable independently of the section 36, in particular can be lifted off the valve seat 16 while the section 36 is still in contact with the valve seat 16. Furthermore, the valve opening 18 has an expanding flow cross-section in the flow direction from atmosphere A to atmosphere B with flow areas 38, 40, the flow area 38 lying in front of the flow area 40 in the flow direction and having a smaller cross-section than the cross-section of the flow area 40 merges conically into the flow area 40. A uniform cross-section over both flow areas 38, 40 is, however, just as conceivable as a narrowing from atmosphere A to atmosphere B.

The relevant valve opening cross-sectional area q _A , which is closed and released by the disc 14, is arranged at the point of confluence directly on the valve seat 16. Accordingly, the valve opening _{cross-sectional area q A} essentially corresponds to the cross-section of the flow region 38.

In the exemplary embodiment in FIGS. 6 and 7, the valve seat 16 protrudes from the separating material 15. Accordingly, in the closed position Y, the disk 14 only rests against the valve seat 16 protruding from it, but not against the remaining sections of the separating material as 15. However, a flat surface without a protruding section of the valve seat 16 is also conceivable.

In contrast to FIG. 6, in FIG. 7 the liquid FL has again accumulated to a higher liquid level. As described for FIG. 3, this becomes a vertical upward buoyancy force exerted on the float 12, whereby the float 12 and thus also the disc 14 move vertically upwards.

Because of the point of application of the buoyancy force eccentric to the valve seat 16, the section 34 of the disk 14 located at the stick 12 is first raised. The valve opening _{cross-sectional area q A} is gradually released, whereby the accumulated liquid can be released over the gradually larger open cross-sectional area of the valve opening cross-sectional area q _A.

As already explained above, the valve opening force required then decreases due to the partial pressure equalization and the disc 14 is gradually lifted from the section 34 to the section 36 from the valve seat 16. In this way, the disk 14 as an exemplary closure element of the float valve 10 moves from the fully closed position Y to the fully released position X without the entire, maximum valve opening force having to be applied at once, as with a rigid closure element.

Claims

PATENT CLAIMS 1. A float valve (10), in particular for draining condensate in a medical compressed air system, comprising: a) a float (12); b) a valve seat (16) which defines a valve opening (18a, 18b; 18) with a valve opening cross-sectional area q _A; and c) a closure element (14) for releasing and closing the valve opening cross-sectional area q _{A of} the valve opening (18a, 18b; 18), the closure element (14) between a fully released position X and a fully closed position by means of the float (12) Position Y is controllable; characterized in that the closure element (14) is elastic and part of a partial opening mechanism which is set up, due to the elasticity of the closure element (14), to reduce the valve opening cross-sectional area q _{A of} the valve opening (18a, 18b; 18) between the fully closed position Y and to release the fully released position X successively. 2. The float valve (10) according to claim 1, characterized in that the elastic-specific closure element (14) at least partially has a band (14) for releasing and closing the valve opening cross-sectional area q _{A of} the valve opening (18), the band (14 ) is set up to be removed from the valve opening (18) with peeling between the fully closed position Y and the fully released position X in order to _{successively release the valve opening cross-sectional area q A of the valve opening (18) by the peeling removal.} 3. The float valve (10) according to claim 2, characterized in that a holding means (24, 26) is provided on the float (12) and / or on the valve seat (16), by means of which the band (14) can be attached to the float (12) or to the valve seat (16). 4. The float valve (10) according to one of claims 2 or 3, characterized in that the belt (14) is a closed belt. 5. The float valve (10) according to any one of the preceding claims, characterized in that the closure element (14) can be positioned eccentrically to the valve opening (18) at least in the fully closed position Y and can thus be attached to the float (12) unevenly is that when controlling the closure element (14) between the fully closed position Y and the fully released position X, the closure element (14) is removed from the valve opening (18) peeling and the valve opening cross-sectional area q _{A of} the valve opening is removed by peeling (18) will be released successively. 6. The float valve (10) according to any one of the preceding claims, characterized in that the valve opening (18a, 18b; 18) each has a plurality of cross-sectional areas of different sizes, the closure element (14) in one direction (99) from the valve opening (18) can be peeled off, in which the closure element (14) can first be peeled off from the smallest cross-sectional area of the valve opening (18a, 18b; 18). 7. The float valve (10) according to one of the preceding claims, characterized in that the float valve (10) has several valve openings (18a, 18b) and the valve openings (18a, 18b) are closed and released by a common closure element (14) can be. 8. The float valve (10) according to one of the preceding claims, characterized in that the float (12) directly controls the closure element (14) without the aid of a Vorsteuerven valve. 9. A compressed air system, in particular for providing compressed air for the compressed air operation of dental devices, with a float valve (10) according to one of claims 1 to 8. 10. A dryer for a compressed air system with a float valve (10) according to any one of claims 1 to 8 for draining condensate.