DE1063432B - Pressure reducing valve for low-noise and low-vibration throttling of flowing, gaseous media, in particular for reducing the pressure of steam - Google Patents

Description

GERMAN

The invention is concerned with a pressure reducing valve which provides a low-noise and low-vibration throttling of gaseous media, in particular a pressure reduction of steam, even at high pressures, pressure gradients and throughputs, z. B. at 5 a pressure of 150 atmospheres and higher in the supply line, a pressure ratio of 6: 1 and more and at Throughputs of 180 t / h and above.

In the usual throttle devices, the steam to be reduced is when passing through a constriction relaxed with subsequent expansion space. Noise is generated during this reduction process and vibrations, which increase significantly with increasing throughput and increasing pressure gradient can and often not only to the strongest acoustic annoyance, but also to the destruction of the Valve, downstream internals and pipelines. As a remedy, was at high Pressure drop made a division into stages with critical or almost critical pressure drop. the Stages are partially activated by throttling devices other than valves, such as e.g. B. perforated cylinders, diaphragms, Sieves or perforated plates, which can also have a rectifying effect, are formed. Furthermore was tried to reduce the To achieve noise and vibration.

The use of sieve plates in connection with safety valves is already known per se. at one provided with a counter pressure chamber and auxiliary valve known safety valve are in the outlet pipe in series connection three throttle plates, which are provided with holes and thus represent sieve plates. These sieve plates are supposed to here primarily as a throttle device for relaxation of the Drude to serve. It is not intended to use these orifice plates to reduce noise to use. However, a passage opening in each of the individual plates is offset from one another there as well intended.

An arrangement has also become known which relates to the exhaust of an internal combustion engine relates. In this case, noise attenuation is to be effected, and the sound absorption takes place with it The help of sound-absorbing materials such as wadding, felt, glass wool, etc., to maintain the dimensional stability of perforated metal sleeves, e.g. B. in spherical shape, are surrounded. The pressure drop at Flow should naturally be kept as low as possible because of the associated loss of power will. A throttling effect should thus be avoided as far as possible.

A device for damping noise in pressure lines has also become known.

Pressure reducing valve for noise

and low vibration throttling

flowing, gaseous media,

especially for pressure reduction

of steam

Applicant:

Siemens-Schuckertwerke

Stock corporation,

Berlin and Erlangen,

Erlangen, Werner-von-Siemens-Str. 50

Dipl.-Phys. Dr. rer. nat. Eberhard Koppe
and Dipl.-Phys. Dr. rer. nat. Ernst-August Müller,

Göttingen,
have been named as inventors

It is a design in which the closure piece is a piece of pipe limited by seven is connected upstream, which contains loose mass particles made of solid material. Such mass particles can be designed as glass beads or consist of shot or faceted corpuscles. Facilities to dampen the turbulence in the incoming flow or to remove swirl movements in the intermediate flow, i.e. to calm the flow, are also used in reducing valves frequently used. How far they contribute to damping the sound vibrations is at the consideration of the present invention insofar as it is of one of the shut-off points downstream reducing device is assumed, in which the turbulence in the reducing device should not be attenuated, but should be used to reduce the pressure.

Finally, there is a device for damping impacts of gases or liquids flowing through Transverse guide surfaces switched on in the pressure medium line have become known that the flowing Spread center radially. Such a device is intended to protect pipelines, pressure gauges, etc. serve for sudden pressure surges. This is achieved with the known device that the steep Front of such a pressure surge in the pressure

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medium is reduced. The opposing branching system directly behind the shut-off or the guide surfaces are to be laid with interlocking control points, but a certain amount of transverse to the radial flow direction can be allowed, the size of which is provided by math waves that define the friction of the flowing mechanically leaves. Accordingly, the agent can increase on the guide surfaces and extend the flow distance e between the narrowest cross-section on the flow path between the guide surfaces. A place behind the valve seat of the closure piece and throttling is not desired and should be largely avoided even at the beginning of the labyrinth system. _that ^ _{not greater} ^ _{& h g = 2} | // _{wobd the effect}

In contrast to one of the mentioned be \ π

known arrangements in which an already existing io seed cross-section of the outlet opening of the shut-off

Sound is supposed to be reduced by absorption.

In the case of the invention, it is important to prevent the waves of sound from being caused by the direct approach of the labyrinth reduction of gaseous media to the shut-off point. The known embodiments of throttle device measurements, which determine the length of the cavity vibrations, are made so small that their services also have in common that free jets excitation practically no stimulating frequencies of high velocities occur whose kinetic ones are more present in the flow. With an energy through free jet mixing in heat over value for e of 5 cm would be led approximately with the occurrence. The 20 order of 10 kHz generated by the uncontrolled decay of the vibrations with a frequency in the size free jet and the mixing process, the intensity of which is no longer great after pressure fluctuations ^ are the main source of the measurements made.
noise and vibrations. In the above-mentioned known safety other strong noise and vibration sources valve with back pressure chamber and auxiliary valve occur in the case of unfavorable impact of the free jets as mentioned above, in the outlet pipe a number of the walls of the valve housing or on unfavorably an- 25 throttle plates used. Even if you have the installed internals on. A further important source of interference are cavities labyrinth system, in which the occurrence of sound-absorbing effects on the low-pressure side of the valve housing is created by the above-mentioned internals, there is an essential difference. In these cavities, with dimensions which are favorable compared to the invention as these throttle plates, cavity vibrations cannot form directly on the valve seat of the closure. If there is a vibrating piece in the apparatus, connect it. As a result, a free jet can occur in the known capable part with a natural frequency, which is located in the vicinity, which is due to the creation of such cavity oscillation, so the finding can be avoided by destroying the labyrinth apparatus very quickly. 35 system directly to the valve seat of the Vexschluss-The invention is based on considerations that the piece connects or within a maximum of the occurrence of pressure fluctuations, which is arranged at the impermissible distance, which the regulated disintegration of free jets and the representation of cavity resonances within the Hearing mixing process are generated and the noise area largely excludes. In contrast, and must cause vibrations, must first be avoided in the known arrangement with the occurrence of. The free jet mixing must therefore no longer be used for cavity resonance in the audible range, calculated as relaxation of the steam.

but the flowing medium will be explained with the aid of the drawing, the invention will be explained in more detail at low speed in a labyrinth-like manner. The figure shows an execution branch system under constant direction and 45 example in its essential for the invention speed changes by dividing for a low-noise controllable reducing inner turbulent and molecular friction on a valve according to the invention. Relieved immediately below the specified final pressure. The free-jet valve cone ν is a branching system consisting of several plates s mixing as the main source of interference. The steam does not appear at all for the expansion of the steam through the first plate, which is drawn in by a large number of more. The invention now consists in opening openings α through and then encountering the next that in a pressure reducing valve with the noise plate s ₂ , the openings a of which are attached so that and low-vibration throttling of flowing gas openings of the first plate S _{1 are} closed parts shaped media, especially to reduce pressure, face _{the next plate ^ 2.} The steam from steam, 55 arranged behind the closure piece, is thereby dammed up and forced to a speed-throttle section as a labyrinth-like change of direction and branch. This process system with the properties described is repeated in the case of which is looked at in the same way, and is located immediately behind the valve-arranged plate ₃ and the subsequent seat of the closure piece. So that means plates. The turbulent friction caused by the speed and direction of the labyrinth-like branching system so tightly ^δο device change lies behind the valve seat of the closure piece, that inside the flow ensures the relaxation of the occurrence of a described free jet effect steam.

is avoided. As shown structure-borne noise measurements

When the labyrinth-like branching system is in place, it is beneficial if the distance between

⁶ 5 see the shut-off point and labyrinth-like bifurcation immediately behind the shut-off or control point.

finds, a free jet, which is dimensioned by the impact and movement system so that the distance e, such as

Zfl h Sö /

Decay could still produce disturbances, between the _{above mentioned} ^ _{& ßer becomes d £} i // _{wobd f}
Shut-off or regulating device and labynnth system over- ° γ π
not arise at all. If it does not succeed, for example effective cross-section of the outlet opening of the deflector for structural reasons, the labyrinth-like 7 ° blocking point represents. The dimension e is up to the loading

Claims (4)

start of the top plate S1. By suitable dimensioning of the distance ζ between the individual plates ί and by specific dimensioning of the openings a>, further improvements in the noise-dampening effect can be brought about. In general, efforts will be made to keep the individual openings small. The total free passage cross-section of a plate can be expanded from plate to plate by adding new openings - as in the drawing - or by enlarging the individual openings so that the speed of the steam remains low in the entire system including the exit from the system, which proved to be very beneficial in measurements. The free cross-section of the individual passage openings in a plate can optionally be selected to be less than 100 mm2. The expansion of the system from plate to plate makes it possible to reach the cross-section q of the final drain pipe at the end of the reducing valve. This means that the overall length of the valve can be kept short; the downstream diffuser-like extension pieces, which in turn can often act as a sound source by detaching the flow on the wall, are avoided. As the experiments have also shown, with such a vapor pressure reducing valve according to the invention, by avoiding the free jet mixing that occurs in the usual known throttle devices and by utilizing the internal turbulent friction, there are now practically no undesired noises and vibrations in its place. By arranging the labyrinth system directly behind the shut-off point, undesirable vibrations in the auditorium could be completely avoided in practice. If a labyrinth-like branching system is used as the throttle section, the constant speed and direction changes caused here can also be implemented by devices other than those described above. Accordingly, other arrangements can also be used, e.g. B. a series of coaxial cylinders. It is also possible to provide other guides for the openings α in the plates than is shown in the drawing. For example, inclined or twisted openings should be considered. PATENT CLAIMS: 1.Pressure reducing valve with low-noise and low-vibration throttling of flowing gaseous . ger media, especially for reducing the pressure of steam, arranged behind the closure piece Throttle section, characterized in that a labyrinth-like branching system is used as the throttle section is provided immediately behind the valve seat of the closure piece. 2. Valve according to claim 1, characterized in that the distance between the closure piece and the beginning of the branching system does not exceed a value of e = 2JM-, wherein / is the effective cross section of the outlet opening of the control or shut-off point. 3. Valve according to claim 1 or 2, characterized in that in a known manner the Branching system, as a labyrinth through planes layered one on top of the other at a short distance or curved plates are formed with through openings and the openings of two successive ones Plates are offset from one another, so that the from the opening of an upstream The beam emerging from the plate impinges at least partially on a full area of the following plate. 4. Valve according to claim 3, characterized in that the flow cross-sections in the successive plates in order to maintain a low flow velocity increase, in particular by increasing the number of passage openings. Considered publications:
German patent specifications No. 270 025, 281231,
142; Swiss Patent No. 261 459;
French patent specification No. 785 013. 1 sheet of drawings © 909 6G7 / 208 8.59