DE1095672B - Closing process for the shut-off device of the pressure line of a centrifugal pump system, especially storage pump system and system for carrying out the process - Google Patents

Description

GERMAN

The invention relates to a closing method for the shut-off device of the pressure line of a centrifugal pump system, especially storage pump system, in which process the flow cross-section of the Shut-off element during the period from switching off the pump motor to the first minimum of the line pressure fluctuations the passage of time rapidly and reduced to a fraction of the full flow cross-section is set. The invention also relates to a storage pump system for implementation of the process, with a shut-off device located in the pressure line of the pump.

It is known that when the pump motor is switched off, one of the pump in the pressure line occurs Direction to the headwater running negative pressure wave, which at the connection point of the pressure line the upstream water is reflected, experiences a phase jump of 180 ° and as an overpressure wave in In the direction of the shut-off element and pump. Here it is reflected anew and runs again to the upper water, etc. Pressure fluctuations therefore occur at the shut-off device.

In known methods and systems of the type mentioned, ■ - after the initially strong Reduction of the passage cross-section of the shut-off device to, for example, 10 to 15 * / »of the full one Cross-section in the time between switching off the pump motor and the occurrence of the first Pressure minimum - the passage cross-section then slowly and continuously further reduced, until the organ is completely closed. In this case, as the member controlling the closing process, for example a fixed orifice located in a line for a servomotor of the shut-off device Ü Durchlaßqunitte or one attached to a rod of a slide, on further hydraulic Controls acting comb, namely an inclined surface used. The closing process (the Closing law) thus runs independently of the pressure in the pressure line.

In contrast to the known method mentioned and the associated systems, the method according to the invention consists in that the passage cross-section of the shut-off element is only further reduced during the pressure decrease intervals following the first pressure minimum until the element is completely closed. Correspondingly, in the system for carrying out ^{1 of} the method, a device is provided for automatically reducing the flow cross-section of the shut-off element only during intervals of decreasing pressure in the pressure line. According to the method according to the invention, the closing-closing method following the first pressure minimum of the pressure fluctuations occurring at the shut-off element is used

for the shut-off element of the pressure line

a centrifugal pump system,

especially storage pump system

and facility for implementation

of the procedure

Applicant:

Sulzer Brothers Aktiengesellschaft,
Winterthur (Switzerland)

Representative: Üipl.-Ing. H. Marsch, patent attorney,
Schwelm (Westphalia), Drosselstr. 31

Claimed priority:
Switzerland from March 11, 1959

Jean Due, Effretikon, Zurich. (Switzerland),
has been manned as an inventor

Process controlled depending on the pressure in the pressure line. The passage area is only is further reduced during pressure decrease intervals, in the remaining intervals of pressure increase it becomes either kept constant or enlarged a little. Thus, the passage cross-section in the first one is on switching off the pump following maximum pressure - provided that the passage cross-section is of the same size at the first, 'the pressure minimum following the shutdown - in the inventive Method larger, whereby the amplitude of the first pressure minimum is smaller. But with that the Thickness of the pressure line pipes can be kept lower.

The larger passage cross-section present at the first pressure maximum corresponding to the one according to the invention It is true that the method has the consequence that the pump which penetrates the pump at this time is reversed The amount of water flowing is also greater, so that the pump, if no further action are hit, thereby comes to a standstill more quickly and then rotated in reverse becomes, which is undesirable for various reasons. However, if you have this disadvantage does not want to accept, expediently in the method according to the invention during the

009 679/326

switch the pump or (and) the pressure decrease following the first pressure maximum, the shut-off device be brought relatively quickly to a smaller passage cross-section, with a closing curve gradient that is greater than that of the corresponding intervals of the closing curve of the known Process in which the flow cross-section is immediately continuous from the first pressure minimum is further reduced.

By the pressure-dependent designed method according to the invention, the locking law, namely the Curve of the respective passage cross-section plotted against time, the fluctuations in pressure automatically adjusted in the pressure line. This is also important if several are connected in parallel Pump groups are present, whereby the time course of the pressure fluctuations in comparison to which is changed when using a single, identical pump.

By way of comparison, it is noted that a system is also known in which there is a shut-off element between the pump and the pressure line a slide is installed. When the water level of the suction-side water reservoir drops below a certain amount, the slide is initially closed automatically, after which the shut-off device the pressure line in still water (without flow) brought into the closed position and the pump is stopped. This is intended to avoid pressure fluctuations.

A system is also known in which the closing process of the shut-off element is adjustable Area is automatically delayed, but is still continued continuously. Last for the two mentioned, known systems, the closing process is similar to that mentioned above in the first place known systems, carried out independently of the current pressure in the pressure line.

Finally, a system is also known in which a hydraulic servo cylinder for the shut-off element is in connection on the one hand with the working space of the pump and on the other hand with the pressure line, so that the piston of the servo cylinder depending on the difference in the two-sided pressures in one or other end position goes and thus the shut-off element is held in the closed or open position. The shut-off device is activated depending on the pressure in the pressure line, but it is once the closing process has been initiated, also continuously regardless of the current one The amount of pressure that changes several times as a result of the pressure waves is guided into the closed position.

Further features of the invention emerge from the following description of exemplary embodiments in connection with the partially schematic drawing and the claims.

Fig. 1 illustrates part of a storage pump system on the basis of the inventive Procedure is explained;

FIG. 2 explains the closing law of a known method, FIG. 3 that of the method according to the invention;

4 shows the most important control parts for carrying out the locking method according to the invention in a simplified form Representation again;

Fig. 5 is a related detail and

FIG. 6 shows an embodiment modified in comparison to FIG. 5.

A feed line 2 is from an underwater 1 of a storage pump system to one of one Three-phase motor 3 driven centrifugal pump 4 out. From her leads a slide 5 containing Pressure line 6 to an upper water 107. The pressure line 6 is connected to the upper water 107 at 108.

On the two abscissas of FIGS. 2 and 3 is the time t, on the ordinate of both figures belonging to the upper i-abscissa the current pressure p prevailing on the slide 5 and on the ordinate belonging to the lower i-abscissa the current pressure Passage cross section D of the slide applied. The curve P ₁ drawn out in FIG. 2 shows the pressure profile at the slide 5 according to a known method, while the curve p ₂ drawn out in FIG. 3 shows the pressure according to the closing method according to the invention. The curves shown in dashed lines illustrate the size of the respective passage cross-section, namely the curve in the known method is designated with A, that in the method according to the invention is designated with B.

The slide 5 contains a fixed in the line 6, conical hollow body 7 (Fig. 4), in which a bell-shaped closing member 8 can be horizontally pushed back and forth in the figure. If that Link 8 with the seat positions 9 rests on the line 6 at 11 when shifted to the left, is the slide 5 completely closed. The slide is controlled by a control cylinder containing a pressure piston 12 13 hydraulically operated. On the right-hand side in FIG. 4, cylinder 13 is connected via a line 14 the pressure line 6, on the left side via a throttle member 15 of adjustable flow cross-section containing line 16 with an automatically actuated shut-off element 17 having pressurized oil supply line 18 connected. In addition, the left side of the cylinder 13 is connected via a line 19 a main control valve 21-connected, which has a Line 22 is connected to a pressureless oil drain line 23. Line 18 also leads to one Fine adjustment valve 24, as well as the line 23. The valves 21, 24 contain electromagnets 25, 26 actuated pilot control pins 27, 28 which work together with control pistons 29, 31 which can be moved up and down in the drawing, which channels 32, 33 of slightly larger passage cross-section and apertures 34,35 of in comparison, have a small passage cross-section. The electromagnet 25 is in the circuit 36 one with its control coil in the circuit 37 (Fig. 1) of the pump motor 3 lying relay 38, the electromagnet 26 in circuit 39 of a relay 41, the control coil of which in circuit 42 is one of one in Fig. 4 as a whole with 45 designated Bourdon tube from actuated electrical contact 44 (Fig. 5) lies.

The Bourdon tube 45 is via lines 46, 14

connected to the pressure line 6. At the free end 47 of the thin sheet metal resilient, slightly widening tube 45 under pressure, a toothing 48 is attached, which with a Gear 49 is in engagement, on the axis 51 of which one half of the contact 44 is formed, the metallic Pointer 52 is firmly mounted. On a not shown, loosely pushed on axis 51, not rotating with it, that is, the stationary and rotationally fixed sleeve is also a stop 53 and the other half of the contact 44 forming stop 54 supporting drum 55 is resiliently stretched such that the drum 55 and so that the stops 53, 54 only when the wheel 49 is rotated and the pointer 52 is pivoted into one or in another direction when the pointer 52 rests on one of the stops 53, 54 and is swiveled further. As long as the tip of the pointer 52 is free between the stops

53, 54 located gap moved, the stops 53, 54 remain at rest, so are not around the Axis 51 pivoted.

The known method is as follows. The motor 3 of the pump 4 is switched off and then the flow cross-section of the slide 5 in the time ij (curve section 80) which has elapsed up to the first pressure minimum 61 to the cross-section D _3, which is approximately 15 ° / »of the full cross-section D ₁

Beat 53, 54 can also be pivoted to the left and take along the associated drum 55, which is on the stationary sleeve carrying it slides. Magnet 26 thus remains energized, valve 40 open.

As soon as the pressure p ₂ decreases again after reaching the first maximum 64 ', the Bourdon tube 45 contracts again. Pointer 52 is pivoted to the right in FIG. 5 and is initially set up by the on (FIG. 2), namely via stroke 53, not shown, lifted. Both stops 53, 54 become control parts. The passage cross-section is then not pivoted until the pointer 52 hits the stop 54 evenly and continuously at the time t ₂ -t _1. The time which elapses until, in accordance with section 63 of curve A , the pointer 52 continues to decrease when the pressure decreases at a standstill. The first pressure maximum 64 has one of the parts 53, 54, 55 which comes to contact 54, has an amplitude 65. The section 63 of the closing curve A 15 FIG. 3 is designated by t _% -t ₂ and is drawn too large, the known method runs independently From now on contact 44 is closed. As a result, the pressure present in the pressure line becomes />_1; Via relay 41, the current in circuit 39 is broken below, as shown in FIG. 2, several maxima and minima, so magnet 26 is de-energized. The shows now falls before the slide 5 is completely closed. Pilot pin 28 from, and valve 40 is closed.

In the method according to the invention there are 20 sen. In the spaces 85, 83 of the fine adjustment valve 24, the control parts during normal pumping operation can, due to the diaphragm 35, have the same pressure in the position shown in FIGS. 4, 5; adjust the organs so that the piston 31 together with the 17, 15 are in a certain throttle position, so the valve 40 is closed holding pin 28 downwards that in lines 18, 16 and in the space 71 of the cylinder goes until the extension 76 opens the bottom 77 of the valve 13 a certain excess pressure compared to the pressure 25 24 is seated. There is now a connection to the line in room 60, through which the slide 5 is in positions 18, 23, so that the oven position previously drawn in room 71 is maintained. Contact 44 seeing pressure under the throttle effect of the organs is open, pointer 52 is in the space 17, 15 slowly continues to sink and the passage cross between the stops 53, 54, circle 42 and the cut of the slide 5 - under repeated moving control coil of the relay 41 are de-energized; The movement of the piston 12 to the left in FIG. 4 is further arranged so that circuit 39 and the electrical power drop _{(time interval J 4 -J 3} , section 81 of curve B magnet 26 in this position of the parts under power in Fig. 3).

are. Likewise, the electromagnet 25 is also exceeded when the second pressure minimum 82 is on and

switched pump motor 3 under power. The pressure in the slide 5 in the following time control pins 27, 28 are then in the drawn upper interval ί ₅ -ί ₄ again, so the pointer 52 is in ren position, in the space 20 with channel 32 and space Fig. 5 lifted from the stop 54, contact 44 that is 83 has a connection with channel 33, the pilot valves are open, circuit 42 is de-energized, circuit 39 is energized 30, 40 are open. Through the diaphragms 34, 35 can set and the pilot control pin 28 in FIG. 4 moves upward in the spaces 50, 85 slightly higher pressure. Thus channel 33 of the valve 24 is built free than in the spaces 20, 83, so that the control 40 is given, so that the connection between the spaces 83, pistons 29, 31 are in the upper position shown. 84 exists and the something that is still present in space 85.If the motor 3 is switched off, the higher electromagnet 25 maintained by the diaphragm 35 is de-energized via the relay 38, so that pressure is used to push the piston 31 to the pilot pin 27 going down and the pre-tax to move up. The lines 18, 23 are thus valve 30 is closed. Now, 20 of the main valve provisionally not builds up in the 45 again interrupted, the closing member 8 in Fig. 4 spaces 50, 21 the same pressure more further moved to the left, so that piston 29 together with the valve passage cross section D ₄ so During the time t _s -t ₄ 30 in the closed position holding pin 27 goes down, held constant (section 89). until the stop 75 on the bottom 73 of the valve 21 Now the pressure rises to the third maximum

rests. The lines 19, 22 are then connected to one another 50 86, with the pointer 52 rotating to the left, connected so that the pressure in space 71 of the control stroke 53 is reached and is then removed when the cylinder 13 moves further to the left. As a result of the overpressure prevailing in the supply of both stops 53, 54 to the left with lines 6, 14 (line decreases. After pressure has been reduced in line 6), piston 12 is now with the closing and impact of pointer 52 on the Stop 54 member 8 in Fig. 4 · - at the same time t _x (Fig. 3) 55 circuit 42 receives power again, circuit 39 is power.

as with the known method - pushed so far to the left until the tip 72 enters the opening 74 protrudes. This interrupts the connection between space 71 and lines 19, 22, 23, in space 71 and

go, parts 28, 31 go down, and the connection between the lines 18, 23 is re-established, so that the slide 5 under the line pressure in lines 6, 14 and left movement of the

Lines 16, 18 thus build up the same pressure on 60 parts 8, 12 during time t _e -t ₅ completely in the same way as in space 60 of cylinder 13
so doesn’t move any further to the left.
In this position the passage cross section D is ₅
(Fig. 3), which is about 15Vo of the full cross-section D ₁ as in the known method.

In the now following time interval J ₂ ^ i _{1 the} increases
Pressure p ₂ on the first maximum 64 '. The pointer
52 reaches the stop 53, while the
Bourdon tube 45 expands. The pointer 52 is in
5 pivoted so far to the left that the gates 81, 87 in FIG. 3). At the time i ₂ 'of the first

Goes closed position, in which he rests with his shoulders 9 at 11 (section 87 in Fig. 3).

The passage cross-section of the slide 5 is kept constant in the pressure increase intervals 61/64 ', 82/86 65 (sections 88, 89 in Fig. 3) and only in the pressure decrease intervals 64782 and from 86 each with the path of the pointer 52 from Stop 53 to stop 54 corresponding delay of approximately the amount t _s -t ₂ reduced (from

Pressure maximum 64 ' , the passage cross section D _s in the method according to the invention is still as large as at time I ₁ in the first pressure minimum 61 according to the known method (FIG. 2) and thus greater than that present at the same time i ₂ ' in the known method Passage cross-section D ₅ . Therefore, the amplitude 91 of the first pressure maximum 64 'in the method according to the invention is smaller than the amplitude 65 in the first pressure maximum 64 of the known method.

In a modified exemplary embodiment, the stop 53 is connected to an electrical line 92 drawn in dash-dotted lines. The arrangement is such that when on the pointer 52 on stopper 53 take a different circuit is closed, the closing member of the slider 5 in Fig. 4 pushed by the via not shown control members 8 slightly to the right, the passage cross section during the time t _z '-t ₁ is thus increased somewhat, namely to the amount D ₆ (cf. the curve 62 shown in dotted lines in FIG. 3). Likewise, the passage cross-section can be increased again somewhat in the time t ₅ -t _i. If necessary, the inclination of the closing sections 81, 87 and possibly also that of the initial section 80 can be increased (cf. for example closing curve section C shown in dash-dotted lines).

In another design, instead of a Bourdon tube, a cylinder 93 (FIG. 6) made of dia- or paramagnetic, in any case non-ferromagnetic material, and a bellows 94 connected behind it, is connected to line 46. The cylinder 93 contains a magnetized body 97, which is under the action of two springs 95, 96 and is horizontally displaceable in FIG attracted and guided armature 101 and a lever 99 articulated thereon is pivoted. The switch 98 corresponds to the contact 44 in the design according to FIG. 5. The space 102 in front of and the space 103 behind the body 97 are connected by a bypass line 105 containing a shut-off element 104 with an adjustable passage cross-section, so that the piston 97 is always independent of the respective operating pressure can return to the drawn middle position and only the short-term pressure differences due to the pressure wave act. During the pressure decrease intervals 64782 and from 86, the body 97 is brought into the position shown as a result of the low pressure in space 102 , in which circuit 42 is closed, so that the lines 18, 23 of the fine adjustment valve 24 are connected to one another and the closing element 8 continues afterwards is moved to the left.

The control and regulation processes are not shown and described in detail. Of course, various additional measures must be taken for the adjustment elements, for example to achieve the desired speed and completion of the respective adjustment processes, and also to generate the respective pressure and the pressure differences in the spaces of the valves 21, 24, but these are the rule for every person skilled in the art - and control technology are readily realizable and known.

Claims (4)

Patent claims: 1. Closing process for the shut-off element of the pressure line of a centrifugal pump system, especially storage pump system, in which process the flow cross-section of the shut-off element is rapidly reduced and adjusted to a fraction of the full flow cross-section during the time that elapses from switching off the pump motor to the first minimum of the line pressure fluctuations, characterized in that the passage cross section (D) of the shut-off element (5) is only further reduced during the pressure decrease intervals (64782) following the first pressure minimum (61) until the element is completely closed. 2. The method according to claim 1, characterized in that the passage cross section (D) of the shut-off element (5) is kept constant during the pressure increase intervals following the interval (64782) of the first pressure decrease. 3. The method according to claim 1, characterized in that the passage cross section (D) of the shut-off element (5) is increased during the pressure increase intervals following the first pressure decrease interval (64782). 4. Storage pump system for carrying out the method according to claim 1 or one of the following with a shut-off element located in the pressure line of the pump, characterized by a device for automatically reducing the flow cross-section (D) of the shut-off element (5) only during intervals (64 '/ 82) decreasing pressure (ρ) in the pressure line (6). Considered publications:
German Patent No. 648,910;
German Auslegeschrift No. 1 049 651;
U.S. Patent No. 2,081,860. 1 sheet of drawings 1 009 679/326 12.60