DE8024894U1 - DEVICE FOR SWITCHING COMPOUND COUNTERS FOR LIQUID OR GASEOUS MEDIA - Google Patents

Description

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. W ₁ GOt ₁ LWiTZER DIPL.'ING. FiWi MOLL

β74υ LANDAU / PALATINATE <LANOSTILASSE 5

PO Box 2080 TELEFON 003 41/8 7000, 00 35 TELEX 04E3S33 litfÖWiGSHÄFEN ΪΪ6β2-βΊβ ■ DEUTSCHE BANK lANDÄ-Ü OälS4O0 (BtZ B48 7OOBS)

May 18, 1982 p

Elster AG / Measurement and Control Technology / Ludwigshafen / Rhine

"Device for switching prepaid payers for liquid or gaseous media "

The innovation relates to a device for switching compound meters for liquid or gaseous media. Such compound meters should have a very large measuring range and therefore consist of two assembled individual meters, the main meter and the secondary meter. The main meter only speaks when a certain minimum flow rate is reached at. The smaller flow values must therefore be recorded by the secondary meter. Will a certain Flow limit reached with increasing flow, can by means of a switching device either from the secondary meter can be switched to the main meter or the main meter can also be connected to the secondary meter. The switching device must therefore when this flow limit is reached open the passage of the main meter. When the flow rate falls, it must when it reaches another close the passage of the main meter at a certain flow rate limit.

Both the öffnUngs · ³ and the SöhÜeßvöfgangs for the passage of the main counter must take place very quickly (almost suddenly), otherwise it can happen that the main counter is flown through slowly increasing quantities during the switching process / which is below the response range of the main counter lie".

In known embodiments of such a network counter the closing device for the passage of the main meter through Weight force, spring force or magnetic force closed held. The closing force is opposed by a force that is the product of the force generated by the The pressure loss caused by the respective medium and the respective effective area of the closing element arises. At the predetermined flow limits at which the switching process is to occur, prevails Balance between the closing force and the counterforce generated by the medium.

In the known embodiments are versehiedenar ^ means used to bring about the greatest possible imbalance between the two forces as quickly as possible, whereby either the closing force or the force of the medium or both are changed. This is supposed to mentioned very fast switching when reaching the certain flow limit are caused. So steers to Example in the switching device according to DE-PS 1 077 884 a single rigid flap plate when opening or Closing the passage of the main meter by an additional passage with a larger cross-sectional area the entire amount of liquid flowing through the compound meter (it is a liquid composite meter) must go through, i.e. through the main and the Secondary meter. This additional passage is firmly connected to the valve disc during the switching process

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Pricey part from full opening to a narrow one Gap And vice versa changed. This occurs at this point a sudden additional throttling effect with pressure loss as well as a change in the effective area of the controlling part, or it is omitted * Because of this change this Pressure loss and the active load changes the hydraulic " Lical opening force at the start of the switching process * rather fast * The clamping force does not change or only changes • rather little. As a result, both when opening and closing the passage for the main meter, a sudden, very fast switching forced * The mode of operation of this known device is satisfactory * The additional passage and the part of the valve disk that controls it must, however, be in relation to the cross section the passage of the main meter must be kept relatively large. The space required for such a switching device is therefore considerable.

In contrast, in a further known embodiment • ines switching valve for compound meters according to German Patent 1 960 735 and the associated additional patent 2 157 326 the exclusive changes to the closing forces for changing the equilibrium when the predetermined Flow limits used. In the opening direction the pressure loss always acts on the valve disk of the passage for the main meter and on the surface of a sliding piston for this valve disc. In the closing direction, on the other hand, there are two spring systems ♦ The first spring system is a holding system for the closed position that only applies to a very short first part of the open or the very last Part of the closing stroke becomes effective. This holding system is switched on and off depending on the stroke articulated lever under the action of a tension spring and a conical surface. The second spring system, consisting of from one large and several smaller coil springs !!

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Wiifkt in Söhließrichtüng over "the whole valve stroke on the Valve disc ^ but not with a steady ^ during the closing stroke gen linear force ^ displacement characteristic * With the opening stroke Because of the dec unilaterally frictional connection there is an unsteady characteristic between the valve plate and the sliding piston. The space requirement in the radial direction of this Device is smaller than in the first described \ rt. The necessary axial expansion is also right large, above all, this switching device requires a large number of individual parts that interact in a complicated manner and therefore have to be precisely adjusted to each other.

From CH-FS 449 991 it is finally known, a cup-shaped Provide the main closing element, which, due to its weight, has a double seat-shaped opening for small flows Keeps the passage for the skin counter closed. The entire liquid first flows through a passage the cup-shaped main closing element and then through a passage opening for the secondary meter and finally the secondary meter. With increasing flow and correspondingly increasing pressure loss when flowing through the secondary meter the surface of the main locking member that covers the double seat passage for the main meter is reinforced in the clasp direction on the main passage. So that the main closing organ when the flow limit is reached for the main meter to be switched on, its passage opens, an auxiliary closing device is used, which is in front of the passage of the main locking member is arranged. With the flow of the annular space and this passage, an oil pressure loss occurs, which occurs at the flow limit mentioned in its effect on the auxiliary locking member is to be greater than its weight. Then this should lift and that Close passage in the main closing element and thus the passage ^ Turn off the flow of the secondary meter. In the secondary meter arises

then no more pressure loss, the main closing element becomes no longer pressed on the double seat passage of the main meter, but on the other hand by the entire pressure of the liquid ' in the line, because nothing else could flow, raised, of course with an auxiliary closing device attached, because this is still pressure loss in the raised open position caused in the main stream.

With falling flow and reaching the other flow }

j value limit at which the passage for the main counter again! to be closed, should then the auxiliary closing element produced by it due to not fall in comparison to its weight more adequate pressure drop again, releasing the passage in the main closing member to be to even this can overcome the closing force caused loss through the pressure \ with his weight , fall down \ and close the passage for the main meter. j

The functioning of the switching process with increasing and decreasing flow assumes perfect cooperation of the two closing organs ahead. If the auxiliary closing element does not respond in time with increasing Flow, the flow value limit at which switching is to take place can be considerably exceeded. In certain circumstances is then not switched at all, e.g. if the line pressure of the liquid is low, because the main closing element yes from the pressure loss itn secondary meter and the associated pipe parts on the double seat of the passage is pressed for the main payer. Likewise, there can be considerable disturbances in the case of a falling flow rate in the case of the required Enter the closing process for the passage of the main meter. Finally, there is an essential and inevitable rather there is a pressure drop in the secondary meter.

The innovation is based on the task of a device

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to find the switching of compound meters, which on the one hand has the known metrological advantages, on the other hand but in their external dimensions, especially in their overall length, as small as possible and therefore also so can be kept as light as possible. In order to achieve the greatest possible operational safety few and simple parts required in the device "

will. Finally, at least with a further development of the innovation, it should be possible for the device to be position-independent to be installed and only to provide a single moving part.

The innovation solves this problem with a device for switching compound meters for liquid or gaseous Media when certain limits of the flow rate are reached, with a closing element for the passage of the Main meter which is weight or spring loaded in the closing direction and which can be opened by hydraulic forces, in which the closing member is designed as a double seat valve with seats, with the passage closed for the main counter only the area of the smaller seat or «·

the difference in area between the two seats and when the I is open

The passage for the main meter also includes the difference area or the area of the smaller seat as the effective area of the pressure difference in front of and behind the shooting body is exposed and a bypass is provided for the passage of the main meter.

Here, therefore, only the advantageous use of the flow force of the medium is used and the desired one and necessary very rapid sudden change in the opening force caused by the medium. Such a valve In addition to the advantages mentioned above, it is characterized by the fact that it has a very small size both in radial and axial direction compared to the known **

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th devices. Is it a device? with a spring-loaded closing body of the valve, then its function is independent of the installation position.

The bypass to the passage of the main meter can either be controlled by the closing body of the double seat valve or a special valve can be used to control this Bypasses can be provided.

In an advantageous embodiment of the double seat valve, at least one or both seats can be designed as sliding seats be.

The switching valve is preferably designed as a structural unit that can be seen in the switching valve housing.

To further reduce the overall length, parts of the switching device can protrude into the interior of the main meter. In a further refinement, the switching device, which is designed as a structural unit, can be in the housing of the main meter be housed.

Further features of the innovation and details of the advantages achieved by the same emerge from the following Description of various device examples, which are purely schematic and in the accompanying drawings for example are reproduced.

Fig. 1 shows the longitudinal section through a switching device with weight-loaded Switching valve in closed position, in

Fig. 2 is again a longitudinal shift through a Switching device with switching valve reproduced in a simplified form,

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Fig. 3 is a longitudinal section through a switching device with a spring-loaded switching valve in closed position, in

Fig. 4 shows the same switching device in the open position.

In the embodiment according to FIG. 1, when the flow through the compound meter is low, all the liquid (in the case of a liquid compound meter) flows through the secondary meter and enters the switching device through passage 1 in the direction of arrow 1 'and at 3 in the direction the arrows 3 ^{1 there} again. The passage 2 for the main meter is closed by the closing body 4 designed as a valve disk. This closing body 4 has such a weight that, when the flow rate increases, it is sure to keep it closed until the predetermined flow limit at which the main meter is to be switched is reached. The closing force, which is given by the weight of the closing body 4, is the opening force of the product of the pressure loss that occurs when flowing through the secondary meter ^ and the passage 1 and the annular area as the effective area, which is the difference between the cross-sectional area of the large fcützes 6 and the cross-sectional area of the small seat 7 is created. In fact, there is the same pressure in passage 2 as when entering de £. Medium in the compound meter, in the interior 9 of the switching device, however, the pressure reduced by the pressure loss mentioned, as well as in the hub ^{8 formed by the hub body f} j under the surface of the small seat 7. The spaces 8 and 9 are given a narrow bore 10 in Closing body 4 pressure equalization.

The 'hub body 5 is equipped with an opening 11 which connects the hub space 8 with the passage 2 , which

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is kept closed by vain weight-loaded valve body 12 , the weight load of valve body 12 is so determined that when the predetermined flow limit is reached due to the pressure difference between the space of the passage 2 and the hub space 8, the valve 11/12 is opened.This creates a bypass to passage 2 of the main meter via openings 10 and 11 *

A pressure drop occurs immediately in the narrow bore 10 / which is almost equal to the pressure difference between the space of the passage 2 and the interior 9, since the Ven ^ til 11,12 only one thing very much in order to maintain its open position low pressure drop required. The pressure loss of the secondary meter with its passage 1 therefore acts suddenly as a pressure difference on the surface of the large seat 6 of the closing body 4. The closing body 4 is also suddenly raised and opens passage 2 for the main meter.

When the closing body 4 is raised, a constriction in a passage 13 also comes into effect in a manner known per se, there is an additional throttling with pressure loss, i.e. an additional increase in the opening force until the edge 14 of the closing body 4 has passed the passage 13. If the C ³ SX flow rate through the compound meter continues to increase, the valve continues to open in the known manner.

When the flow rate decreases, the closing body 4 is held with its edge 14 in the passage 13 until the pressure drop occurring in the constriction 13, 14 formed there in its effect on the entire surface of the Closing body 4 as the opening force becomes smaller than that which is always constant due to the weight of the closing body 4 given closing force. Then the closing body 4 sinks

the passage downwards / the throttling effect in the narrow | place 13,14 leaves shortly before the closing body | pers 4 on its double seat strongly after / when sitting on itself, pressure equalization occurs again immediately between the hub space 8 and the interior space 9 through the narrow bore 10, so again only the Ring surface of the closing body 4 effective at the passage, the closing force strongly outweighs the opening force. This means that even when the predetermined flow limit is reached and the flow rate decreases, a very fast, sudden switching causes *

In the embodiment of the switching device shown in FIG. 2, the sequence of the switching process is similar that of the switching device according to FIG. 1. The bypass to passage 2 of the main meter, however, arises here when it is raised of the closing body 4 and thus the formation of an opening over the small seat 7 and over the narrow bore 10. That additional valve 11, 12 is not required.

The fixed hub body 5 with the small seat 7 can, as shown in Fig. 3, also after the discharge side be arranged. The hub space 8 is here over the narrow | Bore 10 in the closing body 4 with the space of the passage 2 | connected for the main meter, so that there is pressure equalization as long as the opening of the small seat 7 is closed is. The pressure difference that arises as a pressure loss in the secondary meter and in passage 1 is effective when the | nem passage 2 for the main counter, i.e. with small passages | flow through the compound meter below the predetermined Here, too, the switching limit of the flow rate to the difference area between the cross-sectional areas of the large seat 6 and the small seat 7.

The illustrated embodiment is equipped with a spring-loaded

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th valve equipped / so that the opening force of the medium the sealing force of those housed in the hub space 8 SdhraUbehfeder 15 opposes, exceeds the opening force as the flow rate increases, the closing force / so the closing body 4 begins to lift off, the small one Seat 7 is opened and bypass 7, 10 comes into operation * Since the small seat 7, because of its very large circumference compared to the narrow bore 10, has a relative to the passage cross section of the even with the smallest opening stroke narrow bore 10 releases very large penetration surface, occurs in the bore 10 immediately a pressure loss due to the only throttled there bypass flow in the amount of already existing pressure losses from the flow through the secondary meter with its passage 1. The hubs "· space 8 is connected to the pressure of the interior 9 via the open seat 7 and the full pressure loss, which was sufficient, the closing body 4 against the closing force to lift the spring 15 suddenly acts as a pressure difference on the much larger cross-sectional area of the large seat 6. The opening force increases through the Suddenly added effective area very strong and grows with the consequent further lifting of the closing body 4 even more when the edge 14 enters the passage. Only after the edge 14 has passed through Passage 13 results in a larger free cross-sectional area again when the closing body 4 is raised further for the flow and the pressure loss decreases again. This creates a balance between the opening and closing force on, the opening switching operation is ended. When the flow rate decreases, the Circuit in the same way as already described in connection with the embodiment of FIG became.

The embodiment of FIG. 3 also shows a

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Summary of the switching valve as a structural unit, which is inserted as a whole into the housing 16 of the control panel ₄ It protrudes into the interior 17 äeä the housing 18 of the main counter / so that an additional seam is machined *

The two seats 6 and 7 are sealed with CHkingen * The larger seat 6 is designed as a sliding seat ^ likewise could also only the small seat 7 as a south-facing seat or both seats be designed as single-cut seats * That depends at least depending on the given operating conditions an opening of the seat 6 before or after opening the zes 7 is desired and how big the difference can be

Claims (7)

β «β ·· ■ £ ■ · · m ■■ .. ti ess 9» ·· PATENTANWÄLTE DIPL.-ING. W. GOLLWITZBR DIPL.-ING. FW MOLL 6740 LANDAU / PFALZ · 1.ANBSTHASaK 5 POSTFACH E080 · TELKFON 06341/87000, 6035 · TELEX 04S3SSS POST CHECK LUDWIGSHAFEN 27 5β2-β7β · DEUTSCHE BANK LANDAU OS 154OO (BLZ 548 700 03) May 18, 1982 Mess - und Regeltechnik, Ludwigshafen / Rhein '! ^ Device for switching compound meters for liquid or gaseous media "^ Protection claims 1) A device for switching from composite counters for liquid or gaseous media in achieving loading \ indefinite boundaries of the flow rates, with a closing member for the passage of the main counter, which is by weight in the closing direction or spring-loaded and is manifest by hydraulic forces, characterized in that that the Schlicßorgan is designed as a double seat valve with seats {6 and 7), with the passage closed for ' ^e the main counter only the area of the smaller seat (7) or the difference in area between the two seats (6 and 7) and When the passage for the main meter is open, the difference area (6-7) or the area of the smaller seat (7) is exposed to the pressure difference in front of and behind the Söhließkörper (4) as an effective area and A bypass (10) is provided for the passage of the main meter is. • > * I 'II ■ ι. . <■ j I ψ t Ψ ψ rrt M # · Jit P · * · ■ »■ · , 11 · · ■ ■ * · ... »ι ι πι ■ · ■ · ■ · 2.) Device according to claim 1, characterized in that that the bypass (10) for the passage of the main meter through the closing body (4) of the double seat valve is controlled. 3.) Device according to claim 1, characterized in that that a special valve (1. '.' * is provided to control the bypass (10) for the passage of the main meter is. 4.) Device according to claim 1 to 3, characterized in that at least one or both seats (6.7) of the double seat valve are designed as a sliding seat. 5.) Device according to claim 1 to 4, characterized in that the switching valve than in the switching valve housing insertable unit is formed. 6.) Device according to claim 1 to 5, characterized in that parts of the switching device in the Protrude inside the main meter. 7.) Device according to claim 1 to 5, characterized in that the switching device designed as a structural unit is housed in the housing of the main meter.