FR2956182A1 - DOUBLE BUTTERFLY VALVE - Google Patents

Abstract

Valve apparatus, comprising a main butterfly valve (2) and a secondary butterfly valve (B) (12) mounted in the butterfly valve (2) of the main valve (A).

Description

In the use of large diameter butterfly valves, by-pass piping and valves are commonly used to balance the pressure of the fluid conveyed between upstream and downstream of the valve before fully opening the valve. main valve to obtain the nominal flow of the installation. This is intended to balance pressures and decrease fluid velocities at the very beginning of opening to preserve the seal from erosion and cavitation. The second advantage is to limit the opening efforts of the main valve. To achieve this function, it is common to make a diversion of the pipework by an upstream branching and a downstream branch connected by a smaller diameter piping on which is installed a balancing valve. This system is also called bypass. This valve device works perfectly well and gives full satisfaction. However, it has the disadvantage of having to install additional piping external to the main piping. Due to the small distance between the upstream and downstream branching, the bypass piping is very rigid. The welding of the connection flanges on this piping must have a very good positioning geometry with a low tolerance of concentricity, angular indexing and parallelism of the flange faces. In order to ensure the tightness of the valve body to obtain a good seal to the connection flanges, the flanges must be able to move relatively relative to one another. For this, we usually install a mounting joint that allows this latitude. Another disadvantage of the external by-pass solution is that the upstream and downstream connections partially disturb the flow of the fluid in the main pipe, in line with the shutter of the main valve. The invention radically overcomes these disadvantages. removing the bypass with its piping, valve and disassembly seal. It makes it possible to balance the pressure before opening at full flow, to obtain an anti-water hammer effect and, more particularly, to limit the hydrodynamic torques in the case of high flow speeds or in the case of flow disrupted by the configuration of the fluid vein and suppress the phenomenon of beats without using a complementary arrangement, when the butterfly is in equilibrium at full opening in a balanced fluid vein. Finally, the invention makes it possible to obtain linearization of the tap flow rate in regulation applications. The valve device according to the invention comprises a first main butterfly valve. It is characterized by a secondary valve having a throttle mounted in the main throttle valve. Preferably, the main butterfly valve is annular and the secondary butterfly valve is centrally mounted in the central hole of the annular butterfly valve, the secondary valve fully occupying the hole. The outer diameter of the secondary valve throttle may preferably be 1 / 2.5 to 1/6 times the diameter of the main throttle valve. The main valve throttle may have a collinear operating shaft and pivot pin and the secondary valve throttle may have a drive shaft and pivot axis collinear with those of the main valve. Preferably the secondary valve throttle shaft is oriented toward the main valve throttle pivot axis and the secondary valve throttle pivot axis is oriented toward the main valve throttle shaft.

According to one embodiment, the axis of pivoting of the throttle of the main valve is provided with a central recess in which the operating shaft of the throttle of the secondary valve passes with sealing. According to one embodiment taking up little space, the body of the main valve with two diametrically opposite extensions, one at the output of the operating shaft of the main valve, the other at the outlet of the operating shaft of the secondary valve, each of the extensions being provided with a plate on which is fixed an actuator which actuates the respective operating shaft. To avoid beating, in the open position of the main valve, the secondary valve is only partially open with an opening angle of preferably between 75 and 85 °. This can be achieved by adjusting the actuator of the operating shaft of the secondary valve accordingly. The device according to the invention is best controlled by means of actuators independently of the operating shafts of the butterfly valves controlled by angular position sensors of the butterflies and by a torque sensor on the operating shaft of the throttle valve. main faucet. The throttle control device of the secondary valve opens this throttle if said torque exceeds a prescribed value. For this same purpose the device can also have a sensor of the pressure difference downstream and upstream in a pipe in which the valve device is mounted or a timer is triggered while the valve device begins to open and close and the throttle valve control device opens the throttle only after a first prescribed time, counted by the timer, has elapsed, when opening the valve and, during a closing of the valve device, the throttle valve control device of the secondary valve opens this throttle valve only after a second prescribed duration, counted by the timer, has elapsed, the first and second times being replaced by first and second prescribed pressure differences. The invention also relates to a method for operating the valve device according to the invention, wherein, during the opening of the main valve, while it turned a positive angular value, the secondary valve is left in a negative angular position, for example at an angular position between 0 and 45 degrees, the secondary valve butterfly can in particular make an angle of 15 to 90 degrees with the main valve butterfly while the main valve is at a single opening angle between 30 and 75 degrees. In the accompanying drawings, given by way of example only: FIG. 1 is a perspective view of a valve device according to the invention. Figure 2 is a sectional view.

The invention finally relates to a method for operating the valve device according to the invention, wherein the closing speed and / or opening of the secondary valve is changed during opening and / or closing of the main faucet. The device according to the invention comprises a main butterfly valve 2 annular A, mounted in a main pipe. It is intended to allow or interrupt the passage of a fluid that can be liquid, gaseous or powdery. The main valve A carries a butterfly secondary valve B 12 of smaller diameter than the outer diameter of the butterfly 2, installed in the central throttle hole 15 of the main throttle 2. The main butterfly 2 ring is maintained in the median axis of the piping , through the body 1 of the valve A, by an operating shaft 3 and a pivot axis 4. This shaft 3 and this axis 4 are collinear 20 and placed in a diametral position of the main butterfly 2 and the pipe 5 and they are perpendicular to the flow direction of the fluid. The secondary butterfly valve B 12 is fixed in the main butterfly 2 in a preferred position where:

• Firstly, the shafts 3 and 13 as well as the axes 4 and 14 are collinear, • Second, the operating shaft 13 is oriented towards the pivot axis 4 of the main throttle 2, while the pivot axis 14 is oriented towards the main throttle shaft 3, • Third, the plane of the body of the secondary valve B is in the main plane of the throttle valve 2, the main valve A. Therefore, when the two butterflies 2 and 12 are in the closed position, they are coplanar. The body of the secondary valve is integral in rotation of the main throttle.

The pivot axis 4 of the main throttle valve 2 10 is provided with a central recess through which the operating shaft 13 of the secondary valve B can pass in a sealed manner, and becomes accessible from outside the main valve body A to Manipulate the butterfly valve B. The body 1 of the main butterfly valve A is equipped with two extensions 6 and 6 'diametrically opposite and located at the outlet of the operating shaft 3 of the main valve and the other, diametrically opposed, to the operating shaft output 13 of the secondary valve B.

Each of the extensions 6 and 6 'of the body of the main valve A is provided with two plates 7 and 7' on which are fixed the actuators which control each of the respective shafts 3 and 13 which perform the quarter-turn movements Ml and M2.

The assembly is thus simplified by the use of a double butterfly valve since one can save all the bypass piping as well as its disassembly seal and the valve.

This saves material, implementation time, but also allows a great simplification of the pipe since all organs are found in line with the main pipe.

This type of valve can be used for different purposes and modes of operation. Indeed because of its particular design, this type of valve can provide different functions: functions called "all or nothing", the butterflies are maneuvered without stopping between the open position and 10 closed and vice versa: • Suppression of the phenomenon of "beats" when the butterfly is in unstable equilibrium due to the full opening in a perfectly balanced fluid vein. • Limitation of hydrodynamic torques in cases of high flow velocity or in cases of flows disturbed by the configuration of the fluid vein. • Hydraulic shockproof called 20-ram. • Balancing upstream and downstream pressures on opening and closing.

Control function, the butterflies can take any position between open and closed position and vice versa. • Linearization of tap flow in control applications.

When a butterfly valve is kept in full open position in a moving fluid vein, it is very often observed an oscillatory movement of the throttle within the limit of the clearances existing in the connection of the throttle valve and its operating shaft. This phenomenon of flapping is due to the flow of the fluid in the piping which is not perfectly laminar and symmetrical and whose deviations of the fluid veins create oscillations.

The butterfly in full opening is aligned with the general direction of flow and is balanced on its axes. Therefore, it can be solicited by these oscillations of the fluid which drives it in movements of very small amplitude at the frequency of the oscillations of the fluid. The range of motion is limited to the value of the sets of butterfly assembly on its axes. These values, although very low, can lead to destructive mechanical fatigue stresses which can lead to breakage of the keys or drive splines, or even to the matting of the throttle opposing surfaces. (see Figure 3)

The device according to the invention makes it possible to eliminate this phenomenon.

To eliminate the vibrations of the throttle in full open position, the solution, shown in Figure 4, is to place the large throttle valve 2 in full open position and to open the small throttle 12 by an angle a ° between 30 ° and 90 ° opening. This arrangement will create on the whole a hydrodynamic torque which will be proportional to the flow and always applied in the same direction. In this way, the games of the coupling of the shaft 3 with the butterfly 2 will always be caught in the same direction and the two parts shaft 3 and butterfly 2 will always be in contact with each other canceling by the same oscillations and thus canceling the risk of fatigue and matting parts.

In the proposed solution the butterflies are controlled, each independently, by a quarter turn actuator. According to FIG. 5, the actuator C controls the largest of the butterflies 2, while the actuator D controls the small butterfly 12. This implies that, when the main butterfly 2 maneuvers, it carries with it the body the second valve B. If the butterfly 12 does not rotate simultaneously at the same speed and in the same direction, the relative position between body and butterfly of the small valve B changes.

In order to perform the function described above, it is necessary to control in an interdependent manner the actuators driving each of the butterflies according to the parameters of the process.

Actuators C and D can be electric, hydraulic, pneumatic, electrohydraulic or electropneumatic. To do this, the actuator C controlling the butterfly 2 of larger diameter is considered as the master actuator and the actuator D is its slave.

According to FIG. 6 the actuators consist of various interconnected components to fulfill the desired functions.

The master actuator C is coupled to the operating shaft 30 to perform the quarter-turn movement M1 necessary for the large-diameter butterfly 2, while the slave actuator D is coupled to the operating shaft 13 to achieve the quarter-turn movement M2 required for the small-diameter throttle valve 12.20 The actuator C is connected to the operating power 21 which can be electric, hydraulic or pneumatic.

The actuator D receives its operating power and its direction of action of the actuator C via the connection 22.

Referring to FIG. 7, the actuator C is equipped with an electronic box 19 incorporating a microcontroller 26 containing an on-board computer program 25. Via the conditioning interface 27, the microcontroller 26 receives the signals coming from dice:

• position sensor 16 of actuator C 15 • position sensor 16 'of actuator D

The control commands of the actuators and the information intended for process supervision are provided by the communication connection 23. This control can be digital or analog in the form of an electrical signal with a current of 4-20 mA or with a voltage of 0 -10V.

The microcontroller 26 which has a time base is equipped with an EEPROM type memory which makes it possible to store the data, the setpoints and the curves generated by the software 24 of the man / machine interface 20.

The on-board program 25 makes it possible to interpret the set values and the values of the physical quantities connected to it in order to deduce the appropriate command (s) from the control pre-actuators of the two actuators C and D.

The algorithm of this function. The limitation of the hydrodynamic torque is shown schematically in Figure 8 for the opening sequence and in Figure 9 for the closing sequence. It describes the operations, conditions and actions necessary for the proper execution of the operation of the double butterfly valve.

This function is an "all or nothing" function which supposes that on an opening order, the valve being in the fully closed position, the butterfly 2 travels its total stroke of 90 ° to reach its fully open position, while on a closing order the valve runs a total stroke of 90 ° in the opposite direction to reach its fully closed position.

It is assumed that the operator in charge of the tap maneuver will have chosen and loaded into the memory 29 the program 24 "throttle stabilization function opened" by the interface 20 and that he has chosen and introduced into the program 25. angle a ° between 30 ° and 90 °.

The valve being closed, the actuator C receives via the communication line 23 an opening command CO which can be of analog form 31 or digital 30. If the order is digital, the signal 30 is sent to a communication interface 32 which will translate this order in proper form to the conditioner 27 before it is processed by the onboard program 25 of the microcontroller 26. Upon receipt of the opening command CO, the program 25 verifies the position condition of the main throttle P2. if the signal from the throttle position sensor 2 indicates a closed position 16 = '^, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates a closed position 16 = 1, the program will check the throttle position condition 12.

The program 25 verifies the position condition of the secondary throttle P12: if the signal from the sensor of. throttle position 12 indicates a closed position 16 '= D', a KLX alarm is generated and the sequence is stopped. if the signal of the throttle position sensor 12 indicates a closed position 16 '= j, the program will initiate the opening of the throttle valve 2 and the simultaneous operation of the throttle valve 12 by checking its relative position at CP12. During the opening of the throttle valve 2, the module SV continuously controls the speed synchronization between the two throttles so that the throttle valve 12 remains closed relative to the throttle valve 2. In the event of divergence greater than 5 °, a KLX alarm is generated.

When SV indicates that we have 16 = 16 and 16, the opening of throttle 12 is initiated by OP12. CP12 continuously compares the angle of the butterfly 12 by the position sensor 16 'until the position a °. The end of sequence O is then triggered.

The valve being open, the butterfly 2 being full open and the butterfly 12 at the angle a °, the actuator C receives via the communication line 23 an opening order CF which can be of 31 or digital form 30. If the order is digital, the signal 30 is addressed to a communication interface 32 which will translate this order in an appropriate form to the conditioner 27 before it is processed by the onboard program 25 of the microcontroller 26.

On receipt of the opening command CF, the program 25 checks the position condition of the main throttle valve P2 if the signal of the throttle position sensor 2 indicates an unopened position 16 = E, a KLX alarm is generated and the sequence is stopped. If the signal from the throttle position sensor 2 indicates an open position 16 = E, the program will check the throttle position condition 12.

The program 25 checks in the position condition of the secondary throttle P12: if the throttle position sensor signal 12 indicates a position different from a ° 16 '# a °, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 12 indicates an open position 16 '# a the program will start closing the throttle 12: FP12

When the secondary butterfly 12 is closed, 16 '= the model FP2 starts closing the butterfly 2 which triggers the synchronization routine SV. In case of divergence greater than 5 ° a KLX alarm is generated.

CP2 continuously compares the angle of the butterfly 2 by the position sensor 16 until the fully closed position of the butterfly 2, 16 = ^ 15 The end of sequence F is then triggered.

When opening or closing a butterfly valve in a moving fluid vein, the flow is disturbed by the throttle profile. These disturbances create parasitic forces which act on this same butterfly by creating a pair which generally tends to close this butterfly. These parasitic forces, and therefore these torques, are a function of the fluid velocity and the configuration of the circuit 25, the flow of which can be disturbed by the geometry of the pipe, or of pipe fittings such as bends, taps, reductions. Converging or diverging sections, or by pumps or valves or valves placed too close to these butterfly valves. The importance of these parasitic couples may be such that it can lead to the locking of the operating actuator during opening.

It is shown in Figure 10 the evolution of the torque of a butterfly valve in a flowless fluid vein, while Figure 11 shows the evolution of the torque of the same valve subjected to a hydrodynamic torque.

Since the curves CA and CA 'are the maximum torques that the actuator can deliver, it will be observed in FIG. 11 that, in the case of the appearance of a hydrodynamic torque HTO' and HTC ', the actuator will not be able to maneuver the valve. , in opening, only up to the angle corresponding to the point X because the resisting torque will be equal to the engine torque which will lead to the setting of the actuator.

The invention proposes to detect parasitic couples and compare them to a limit value in order, if necessary, to correct them by operating the operation of the small butterfly 12 with respect to the position of the butterfly 2 during the maneuver of opening. This maneuver by modifying the incidence of the small butterfly 12 with respect to the main butterfly 2 will modify the flow of the fluid and thus modify the forces on the latter which will reduce the hydrodynamic torque due to the flow. Figure 12 shows the fluid flow in a conventional butterfly valve and Figure 13 shows the flow in a double butterfly valve.

Figure 14 shows the arrangements made to limit the hydrodynamic torque HTO '. In order to limit the importance of the hydrodynamic torque HTO 'to a value acceptable by the actuator, a lower torque curve CA1 of a value F is defined as the value of the setting torque of the actuator CA. When the torque HTO 'of the throttle valve 2 will reach the value of CA1, for example at the point G, the small throttle valve 12 will be maneuvered in opening to modify the flow and reduce the torque HTO'. When the torque is lower than the value CA1, the opening maneuver will be resumed until the next increase of the torque HTO 'as shown in point J. The process will continue as shown at points K and L until the butterfly 2 has reached its full open position at 90 °.

In the proposed solution the butterflies are controlled, each independently, by a specific quarter-turn actuator. According to FIG. 5, the actuator C controls the largest of the butterflies 2, whereas the actuator D controls the small butterfly 12. This implies that when the main butterfly 2 is operating, it carries with it the body the second valve B. If the butterfly 12 does not rotate simultaneously at the same speed and in the same direction, the relative position between body and butterfly of the small valve B changes.

In order to perform the function described above, it is necessary to control in an interdependent manner the actuators driving each of the butterflies according to the parameters of the process.

Actuators C and D may be electrical, hydraulic, pneumatic, electrohydraulic or electropneumatic.

To do this, the actuator C controlling the butterfly 2 of larger diameter is considered as the master actuator 30 and the actuator D is its slave.

According to Figure 15 the actuators consist of various interconnected components to perform the desired functions.

The master actuator C is coupled to the operating shaft 3 to perform the quarter-turn movement M1 required for the large-diameter butterfly 2, while the slave actuator D is coupled to the operating shaft 13 to achieve the M2 quarter turn movement required for the small diameter butterfly 12.

The actuator C is connected to the operating power 21 which can be electrical, hydraulic or pneumatic.

The actuator D receives its operating power and its direction of action of the actuator C via the connection 22.

Referring to FIG. 16, the actuator C is equipped with an electronic box 19 incorporating a microcontroller 26 containing an on-board computer program 25. By means of the conditioning interface 27, the microcontroller 26 receives the 20 signals coming from:

• position sensor 16 of actuator C • position sensor 16 'of actuator D • torque sensor 18 of the operating shaft of actuator C

The control commands of the actuators and the information intended for process supervision are provided by the communication connection 23. This control can be digital or analog in the form of an electrical signal with a current of 4-20 mA or with a voltage of 0 -10V.

The microcontroller 26 which comprises a time base, is equipped with an EEPROM type memory which makes it possible to store the data, the set values and the curves generated by the software 24 of the man / machine interface 20.

The on-board program 25 makes it possible to interpret the set values and the values of the physical quantities connected thereto in order to deduce the appropriate command or commands from the actuator pre-actuators of the two actuators C and D.

The algorithm of this function is shown schematically in FIG. 17 for the opening sequence 15 and in FIG. 18 for the closing sequence. It describes the operations, conditions and actions necessary for the proper execution of the operation of the double butterfly valve.

This function is an "all or nothing" function which supposes that on an opening order, the valve being in the fully closed position, the butterfly travels its total travel by 90 ° to reach its full open position while on a closing order the valve 25 travels a total stroke of 90 ° in the opposite direction to reach its fully closed position. It is assumed that the operator in charge of the tap maneuver will have chosen and loaded into the memory 29 the program 24 "hydrodynamic torque limiting function" by the interface 20. It is assumed on the other hand that the operator will have selected the size and type of actuator actually installed on the valve in order to select the correct value of the limiting torque CAl.

The valve being closed, the actuator C receives via the communication line 23 an opening command CO which can be of analog form 31 or digital 30. If the order is digital, the signal 30 is sent to a communication interface 32 which will translate this order in proper form to the conditioner 27 before it is processed by the embedded program 25 of the microcontroller 26.

Upon receipt of the opening command CO, the program 25 verifies the position condition of the main throttle valve P2: - if the throttle position sensor signal 2 indicates a non-closed position 16 =, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates a closed position 16 = i], the program will check the position condition of the throttle valve 12.

The program 25 verifies the position condition of the secondary throttle P12: 25 - if the throttle position sensor signal 12 indicates an unlocked position 16 '=! L, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 12 indicates a closed position 16 '= 0, the program will start the opening of the throttle 2 and the throttle 12: OP2 and OP12.

The sequence SV controls the speed synchronization of the two butterflies 2 and 12 while simultaneously and continuously the module COHT 'compares the value of the torque OHT' with the values of CA and CA1. • If OTH 'is lower than CA1, the operation of both butterflies is continued. • If OTH 'is equal to CA1, the GA P12 / P2 module is triggered and opens the throttle 12 to decrease the torque OTH'. When the torque has decreased enough, the maneuver is resumed. The process of control and correction continues until the full open position is reached. • If OTH 'is greater than AC, a KLX alarm is triggered and the operation of both actuators is stopped.

When the fully open position of the butterfly 2 is reached, the butterfly 12 is brought back in the same plane as the butterfly 2 and the end of the sequence O is triggered.

With the valve open, the actuator C receives via the communication line 23 an opening command CF which may be of analog form 31 or digital form 30. If the order is digital, the signal 30 is addressed to an interface of communication 32 which will translate this order in adequate form to the conditioner 27 before it is processed by the onboard program 25 of the microcontroller 26. Upon receipt of the opening order CF, the program 25 verifies the position condition of the butterfly main P2. If the signal from the throttle position sensor 2 indicates an unopened position 16 = 1, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates an open position 16 = 11, the program will check the throttle position condition 12.

The program 25 verifies in the position of the position of the secondary throttle P12: if the signal of the throttle position sensor 12 indicates an unopened position 16 '= II, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 12 indicates an open position 16 '= 11, the program will start opening throttle 12: OP12.

The SV sequence controls the speed synchronization of the two throttles 2 and 12 while simultaneously and continuously the COHT module 'compares the value of the torque OHT' with the values of CA and CA1. • If OTH 'is lower than CA1, the operation of both butterflies is continued. • If OTH 'is equal to CA1, the GA P12 / P2 module is triggered and opens the throttle 12 to decrease the OTH' torque. When the torque has decreased enough, the maneuver is resumed. The process of control and correction continues until the full open position is reached. • If OTH 'is greater than AC, a KLX alarm is triggered and the operation of both actuators is stopped.

When the full closure position of the butterfly 2 is reached, the butterfly 12 is brought in the same plane as the butterfly 2 and the end of the sequence F is triggered.

The invention also makes it possible to avoid any hydraulic shocks to the opening and closing of the device according to the invention by controlling the evolution of the flow rate of the fluid as a function of time.

As a general rule, the operation of a butterfly valve by quarter-turn rotation of the shutter, presented the disadvantage of establishing the flow between the two sections of piping at a constant speed of rotation of the operating shaft . This induces that the law establishing the flow rate Q in the pipe, as a function of the opening angle a ° of the butterfly, is a sinusoidal function. See Figure 19. The consequence is that flow increases slowly between closing at 0 ° and the first twenty degrees of opening, while it rapidly increases between thirty and seventy degrees to reach ninety percent of flow. Q. Between seventy and ninety degrees, the flow rate Q evolve much more slowly. The evolution of the flow follows the same curve in the opposite direction when closing from 90 ° to 0 °. The speed of growth or decay of the flow is one of the main sources of hydrodynamic disturbances resulting in hydraulic shocks in hydraulic installations whose gravity can range from the simple disturbance of comfort by generation of flow noise up to the destruction of works of art such as dams, penstocks or water towers whose consequences can be dramatic.

To solve these problems, using a double butterfly valve and dual actuators operating according to predetermined laws described below.

In the proposed solution according to Figure 5, the butterflies are each independently controlled by a specific quarter-turn actuator. The actuator C controls the largest of the butterflies 2 while the actuator D controls the butterfly 12. This implies that when the main butterfly 2 maneuver, it carries with it the body of the second valve B. If the butterfly 12 does not not rotate simultaneously at the same speed and in the same direction, the relative position between body and butterfly of the small tap B changes.

In order to perform the function described above, it is necessary to control in an interdependent manner the actuators driving each of the butterflies according to the parameters of the process. The actuators C and D can be electric, hydraulic, pneumatic, electrohydraulic or electropneumatic.

To do this, the actuator C controlling the butterfly 2 of larger diameter is considered as the master actuator and the actuator D is its slave.

In accordance with Figures 20 and 21, the actuators are comprised of various interconnected components to perform the desired functions.

The master actuator C is coupled to the operating shaft 3 to perform the quarter-turn movement M120 required for the large-diameter throttle valve 2, while the slave actuator D is coupled to the operating shaft 13 to achieve the movement of a half-turn M2 required for the small diameter butterfly 12. The actuator C is connected to the operating power 21 which can be electrical, hydraulic or pneumatic.

The actuator D receives its operating power and its direction of action of the actuator C via the connection 22.

The actuator C is equipped with an electronic box 19 incorporating a microcontroller 26 containing an on-board computer program 25. Via the conditioning interface 27, the microcontroller 26 receives the signals coming from:

• position sensor 16 of the actuator C • position sensor 16 'of the actuator D 20 The actuator control commands and the information intended for process supervision are provided by the communication connection 23. This command can be digital or analog in the form of an electrical signal with 4-20 mA current or 0-10V voltage.

The microcontroller 26 which comprises a time base, is equipped with an EEPROM type memory which makes it possible to store the data, the set values and the curves generated by the software 24 of the man / machine interface 20.5 The embedded program 25, allows to interpret the set values and the values of the physical quantities connected to it to deduce the appropriate command (s) from the pre-actuators of the two actuators C and D.

According to this mode of operation, the hydraulic characteristics of each of the two valves must be adapted to the use. In general, for this application, the flow rate of small valve B is 6 to 30 times lower than that of the flow rate of large valve A. These values refer to the diameter give ratios of 1 / 2.5 to 1/6.

From the graph shown in Figure 22, we assume that both butterflies are closed and the valve is sealed, that the upstream and downstream pipes are full and that the pressure difference between upstream and downstream is maximum.

Maneuvering this valve will therefore consist in opening the small butterfly 12 at a controlled opening speed which will ensure an opening time equal to Tls. As the throttle opening limit signal 12 is triggered, the opening of the throttle valve 2 is then progressively performed according to a controlled opening speed which will make it possible to reach the opening time T2s.

For closing the valve the process is reversed, at time T3s the butterfly valve 2 is controlled closing until the pressure reaches the pressure P2 or the time T4s has elapsed, which triggers the closure of the second butterfly 12.

The closing sequence is completed either when the butterfly 2 has reached its maximum closing position or the time T5s is reached.

The operating times read - TOs and T4s - Tas can be different, as well as the values of Pl and P2 because the hydraulic behavior of the installation can be different in power supply and sectioning.

The algorithm of this function is shown schematically in Figure 23 for there. opening sequence and in figure 24 for the closing sequence. It describes the operations, conditions and actions necessary for the proper execution of the operation of the double butterfly valve.

This function is an "all or nothing" function which supposes that on an opening order, the valve being in the fully closed position, the butterfly travels its total stroke of 90 ° to reach its full open position while on a closing order the valve runs a total stroke of 90 ° in the opposite direction to reach its fully closed position.

It is assumed that the operator in charge of the tap maneuver will have chosen and loaded into the memory 29 the program 24 "opening function with upstream / downstream pressure equalization" by the interface 20. It is assumed by another On the other hand, the operator will then have introduced the necessary values for a smooth running of this function, namely the values of the pressure parameters P1 and P2 and / or of time T1, T2, T4 and T5.

The valve being closed, the actuator C receives via the communication line 23 an opening command CO which can be of analog form 31 or digital 30. If the order is digital, the signal 30 is sent to a communication interface 32 which will translate this order in proper form to the conditioner 27 before it is processed by the embedded program 25 of the microcontroller 26.

Upon receipt of the opening command CO, the program 25 checks the position condition of the main throttle P2. if the signal from the throttle position sensor 2 indicates a closed position 16 = 1, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates a closed position 16 = 1, the program will check the position condition 20 of the throttle valve 12.

The program 25 verifies the position condition of the secondary throttle P12: if the throttle position sensor signal 12 indicates an unclosed position 16 '= E, a KLX alarm is generated and the sequence is stopped. if the throttle position sensor signal 12 indicates a closed position 16 = 11, the program will initiate the opening of throttle 12: OP12. The sequence OP12 simultaneously starts two checks: the control of the pressure P1 or the time T1 CP1 / CT1 the control of the position of the throttle 12 CP12

The escape of these two checks of pressure or time condition, .P1 / T1 and open position of the butterfly 12, ie 16 '= I, are connected to an AND cell that verifies that both conditions are simultaneously fulfilled.

The AND cell then authorizes the opening operation of the throttle valve 2, OP2, which as long as the valve opening position is not reached monitors the time threshold T2 by the cell CT2.

If the time T2 has elapsed without the opening position of the throttle valve 2 being reached, the cell CT2 triggers a KLX alarm. If the time T is less than or equal to the value T2 and the butterfly 2 signals its open position by the signal 16 = ~, the opening sequence is terminated and the cell 0 sends the program the signal "end of 25 opening sequence ".

With the valve open, the actuator C receives via the communication line 23 a closing command CF which can be in the same form as for the opening sequence.

On receipt of the closing order CF, the program 25 checks the position condition of the main throttle P2. if the signal from the throttle position sensor 2 indicates a closed position 16 = 1, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates an open position 16 = 1, the program will check the throttle position condition 12.

The program 25 verifies the position condition of the secondary throttle P12: if the signal of the throttle position sensor 12 indicates an unopened position 16 '= E, a KLX alarm is generated and the sequence is stopped. if the signal of the throttle position sensor 12 indicates an open position 16 '=, the program will start the opening of the throttle 12: FP2

The sequence FP2 simultaneously initiates two checks: • the control of the pressure P2 or the time T4 = CP2 / CT4 • the control of the position of the butterfly 2 = CP2 The escape of these two checks of condition of pressure of time, P2 / T4 and open position of the butterfly 2, ie 16. =, are connected to an AND cell that verifies that both conditions are simultaneously fulfilled.

The AND cell then authorizes the closing operation of the butterfly 12, FP12, which as long as the closed position of the valve is not reached monitors the time threshold T5 by the CT5 cell.

If the time has elapsed without the throttle 12 closing position being reached, the CT5 triggers a KLX alarm.

If the time T is less than or equal to the value T5 and the butterfly 12 signals its closed position by the signal 16 '= 16, the opening sequence is terminated and the cell F sends the program the signal "end of sequence closure ".

The device according to the invention makes it possible to avoid possible hydraulic shocks on opening and closing by balancing the upstream and downstream pressures.

In general, the operation of a butterfly valve by quarter turn rotation of the shutter has the disadvantage of establishing the flow rate between the two sections of piping in a rapid manner. This speed can be a source of hydrodynamic disturbances resulting in hydraulic shocks whose gravity can range from the simple disturbance of comfort by generation of flow noise to the destruction of a structure such as dams , penstocks or water towers whose consequences can be dramatic. To solve these problems, we propose to use a double butterfly valve and double actuator.

In the proposed solution the butterflies are each independently controlled by a specific quarter-turn actuator. According to FIG. 5, the actuator C controls the largest of the butterflies 2 while the actuator D controls the small butterfly 12. This implies that when the main butterfly 2 maneuvers, it carries with it the body of the second valve B. If the butterfly valve 12 is not rotating simultaneously at the same speed and in the same direction, the relative position between the body and the butterfly valve of the small valve B changes.

In order to perform the function described above, it is necessary to control in an interdependent manner the actuators driving each of the butterflies according to the parameters of the process.

Actuators C and D may be electrical, hydraulic, pneumatic, electrohydraulic or electropneumatic.

To do this, the actuation C controlling the butterfly 2 of larger diameter is considered as the master actuator and the actuator D is its slave. According to Figure 25 the actuators consist of various interconnected components to fulfill the desired functions.

The master actuator C is coupled to the operating shaft 3 to perform the quarter-turn movement M1 required for the large-diameter throttle valve 2, while the slave actuator D is coupled to the actuating shaft 13 to make the movement of a half-turn M2 necessary for the butterfly of small diameter 12.

The actuator C is connected to the operating power 21 which can be electric, hydraulic or pneumatic.

The actuator D receives its operating power and its direction of action of the actuator C via the connection 22.

The actuator C is equipped with an electronic box 19 incorporating a microcontroller 26 containing an on-board infomration program 25. Via the conditioning interface 27, the microcontroller 26 receives the signals coming from: 15 • position sensor 16 of the actuator C • position sensor 16 'of the actuator D • torque sensor 18 of the operating shaft of the actuator C 20 • pressure sensor 17 and 17' enabling the pressure difference to be provided by through the differentiator 28

The control commands of the actuators and the information for process supervision are provided by the communication connection 23. This control can be digital or analog in the form of an electrical signal with a 4-mA current or a 0-mA voltage. 10V. The microcontroller 26 which comprises a time base is equipped with an EEPROM type memory which makes it possible to store the data, the setpoints and the curves generated by the software 24 of the man / machine interface 20.

The on-board program 25 makes it possible to interpret the setpoint values and the values of the physical quantities connected thereto in order to deduce the appropriate command (s) from the control pre-actuators of the two actuators C and D.

Depending on the operating mode, the hydraulic characteristics of each of the two valves must be suitable for use. As a general rule, the flow rate of the small valve B is 20 to 100 times lower than the flow coefficient of the 1.5 large valve A. These values refer to the diameter give ratios of 1/5 to 1/15.

From the graph shown in FIG. 26, it will be assumed that the two throttles are closed and the valve tight, that the upstream line is full and that the pressure difference between upstream and downstream is maximum.

Maneuvering this valve will therefore consist in opening the small butterfly 12 and wait before starting the opening of the main butterfly 2, either the upstream-downstream pressure difference has reached a given value P1, or, if the process is perfectly known, that a given time T1s has elapsed since the initiation of the opening order at time TOs. When the parameter concerned is reached, the opening of the butterfly 2 is triggered. The opening sequence is completed either when the butterfly 2 has reached its maximum open position or the time T2s is reached.

For the closure of the valve the process is reversed, at time T3s the butterfly valve 2 is controlled closing until the pressure reaches the pressure P2 or the time T4s has elapsed which triggers the closure of the valve. second butterfly 12.

The closing sequence is completed either when the butterfly 2 has reached its maximum open position or the time T5s is reached.

The operating times T1s - TOs and T4s - T3s can be different, as well as the values of P1 and P2 because the hydraulic behavior of the installation can be different in power supply and sectioning.

The algorithm for this function is shown schematically in Figure 27 for the opening sequence and in Figure 28 for the closing sequence. It describes the operations, conditions and actions necessary for the proper execution of the operation of the double butterfly valve. This function is an "all or nothing" function which supposes that on an opening order, the valve being in the fully closed position, the butterfly travels its total travel by 90 ° to reach its full open position while on one closing order the valve runs a total stroke of 90 ° in the opposite direction to reach its fully closed position.

It is assumed that the operator in charge of the operation of the tap will have chosen and loaded into the memory 29 the

program 24 "opening function with upstream / downstream pressure equalization" via interface 20.

It is assumed on the other hand that the operator will then have introduced the values necessary for a good progress of this function namely the values of the pressure parameters P1 and P2 or / and time Tl, T2, T4 and T5.

The valve being closed, the actuator C receives via the communication line 23 an opening command CO which can be of analog form 31 or digital 30. If the order is digital, the signal 30 is sent to a communication interface 32 which will translate this order in proper form to the conditioner 27 before it is processed by the embedded program 25 of the microcontroller 26.

Upon receipt of the opening command CO, the program 25 verifies the position condition of the main throttle valve P2: if the throttle position sensor signal 2 indicates a non-closed position 16 = 1, a KLX alarm is generated. and the sequence is stopped. If the signal from the throttle position sensor 2 indicates a closed position 16 =, the program will check the throttle position condition 12.

The program 25 verifies the position condition of the secondary throttle P12:

if the throttle position sensor signal 12 indicates an unlocked position 16 ', a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 12 indicates a closed position 16 '= E, the program will launch the opening of the throttle 12: OP12.

The sequence OP12 simultaneously launches two checks

• control of pressure P1 or time T1 = CP1 / CT1 • control of throttle position CP12

The exhaust of these two checks of pressure condition and / or time, Pl / Tl and open position of the butterfly 12, that is 16 '= 7, are connected to a cell. AND summing that verifies that both conditions are simultaneously fulfilled.

The AND cell then authorizes the opening operation of the throttle valve 2 OP2, which as long as the opening position of the valve is not reached, monitors the time threshold T2 by the cell CT2.

If the time T2 has elapsed without the opening position of the throttle valve 2 being reached, the cell CT2 triggers a KLX alarm. If the time T is less than or equal to the value T2 and the butterfly 2 signals its open position by the signal 16 = I, the opening sequence is terminated and the cell O sends the program the signal "end of 30 opening sequence ". With the valve open, the actuator C receives via the communication line 23 an opening command CF which may be in the form of the opening sequence.

On receipt of the opening command CF, the program 25 checks the position condition of the main throttle P2. if the signal from the throttle position sensor 2 indicates a closed position 16 = 1, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 2 indicates an open position the program will check the throttle position condition 12. The program 25 checks the position condition of the secondary throttle P12:

if the signal from the throttle position sensor 12 indicates an unopened position 16 '= -, a KLX alarm is generated and the sequence is stopped. if the signal from the throttle position sensor 12 indicates an open position 16 '=, the program will start closing throttle 2: FP2.

The FP2 sequence simultaneously initiates two checks:

• control of pressure P2 or time T4 = CP2 / CT4 • control of throttle position 2 = 15 CP2 Exhaust of these two checks of pressure or time condition, P2 / T4 and closed position of the butterfly 2, ie 16 = are connected to an AND summing cell which verifies that both conditions are simultaneously fulfilled.

The AND cell then authorizes the closing operation of the butterfly 12, FP12, which as long as the closed position of the tap is not reached monitors the time threshold T5 by the cell CT5.

If the time T5 has elapsed without the butterfly 12 closing position being reached, the CT5 cell 15 triggers a KLX alarm.

If the time T is less than or equal to the value T5 and the butterfly 12 signals its closed position by the signal 16 '=, the closing sequence is terminated and the cell F sends the program the signal "end of sequence of closing ".

We now describe how to perform a flow control function. This function can be broken down into two functions. The first, the simplest is to adjust the position of the butterflies according to a control signal which is usually called "positioner" in the business of industrial valves, while the second proposes to adjust 30 a physical variable of 'a process according to the same control signal, which is called' regulator '.

The purpose of this function is to control the fluid flow through the valve. In general, butterfly valves are not considered as performing in fluids management. Indeed, the authority of this type of tap on the flow is of sinusoidal shape as a function of the opening angle. See Figure 29. This indicates that the ability of the butterfly valve to adjust a flow rate is effective only between 30 ° and 70 ° of opening. The valve according to the invention makes it possible to overcome this defect by linearizing the flow rate by opening the small central butterfly 12 first and then the main butterfly 2 at the end and vice versa when closing. This arrangement makes it possible to reduce the authority of the tap of 40% to a value between 70% and 95% of the race according to the size of the small butterfly. See figure 30. To achieve this function, the flow ratio between small butterfly 12 and large butterfly 12 must be between 1/3 and 1/5. This leads to a diameter ration of between 0.57 and 0.44. In the proposed solution, the butterflies are each independently controlled by a specific quarter-turn actuator. According to FIG. 5, the actuator C controls the largest of the butterflies 2 while the actuator D controls the small butterfly 12.

This implies that when the main butterfly 2 maneuver, it carries with it the body of the second valve B. If the butterfly 12 does not rotate simultaneously at the same speed and in the same direction, the relative position between body and butterfly of the small tap B changes.

In order to perform the function described above, it is necessary to control in an interdependent manner the actuators driving each of the butterflies according to the parameters of the process.

Actuators C and D can be electric, hydraulic, pneumatic, electrohydraulic or electropneumatic. To do this, the actuator C controlling the butterfly 2 of larger diameter is considered as the master actuator and the actuator D is its slave.

According to FIGS. 31 and 32, the actuators consist of various interconnected components to fulfill the desired functions.

The master actuator C is coupled to the operating shaft 15 to perform the quarter-turn movement Ml required for the large-diameter throttle valve 2, while the slave actuator D is coupled to the operating shaft 13 to achieve the quarter-turn movement M2 required for the small diameter butterfly 12. The actuator C is connected to the operating power 21 which can be electric, hydraulic or pneumatic.

The actuator D receives its operating power and its direction of action of the actuator C via the connection 22.

The actuator C is equipped with an electronic box 19 incorporating a microcontroller 26 containing an on-board computer program 25. Via the conditioning interface 27, the microcontroller 26 receives the signals coming from:

• position sensor 16 of the actuator C position sensor 16 'of the actuator D5 • sensor of the physical parameter 33 of the process to be adjusted

The control commands of the actuators and the information for process supervision, via the conditioning interface 27, are provided by the communication connection 23. This control can be digital or analog in the form of a electrical signal with 4-20mA current or 0-10V voltage.

The microcontroller 26 which comprises a time base, is equipped with an EEPROM type memory 29 which stores the data, the setpoints and the curves generated by the software 24 of the man / machine interface 20.

The onboard program 25 makes it possible to interpret the set values and the values of the physical quantities connected thereto in order to deduce the appropriate command (s) from the control pre-actuators of the two actuators C and D.

To perform this function, the control unit of the actuation is connected to the process and receives the position setting instruction by the input 23. This signal is then compared to the measurements of the sensors 16 and 16 'indicating the position of the butterflies 2 and 12. Depending on the difference between the setpoint and the measurement, throttle positioning commands are issued to reduce this difference. When the spread is zero, the shares are canceled until a new spread is noted.

For smooth operation, the limit switch opening signal of the small throttle valve 12 automatically triggers, at point R, the opening of the large throttle valve 2. Likewise in the closing action of the large throttle valve 2, the end-of-travel signal closes. butterfly 2 triggers, at point R, the closure of the small butterfly 12.

To carry out this function, the control unit of the actuation is connected to the process and receives the positioning instruction from the input 23. This signal is then compared to the measurement of the sensor 33 indicating the value of the physical quantity. the process to be settled. Depending on the discrepancy between the deposit and the measurement, throttle positioning orders are issued to reduce this difference. When the spread is zero, the shares are canceled until a new difference is found. .

For smooth operation, the limit switch opening signal of the small throttle valve 12 automatically triggers, at point R, the opening of the large throttle valve 2. Likewise in the closing action of the large throttle valve 2, the end-of-travel signal closes. butterfly 2 triggers, at point R, the closure of the small butterfly 12.

The algorithm of the "Positioning" function is shown schematically in FIG. 33. It describes the operations, conditions and actions necessary for the proper execution of the positioning of the butterfly valves.

It is assumed that the operator in charge of the operation of the tap will have chosen and loaded into the memory 29, the program 24 "function positioning" by the interface 20. This program will be further parameterized by providing the dimension information taps, the type of control signal, digital or voltage or current and the calibration of position sensors.

Referring to FIG. 33 and considering the valve in an indeterminate position, the program receives an input command CE, this instruction is addressed to the reference comparator CpC. This comparator receives, on the other hand, a feedback of the position transfer function F (x) Tr / a which formats the combined signal Cp16 + 16 'which is the image of the cumulative position. two straws 2 and 12 via the position information of the sensors 16 and 16 '. If the module Cpc finds a difference between the CE setpoint and the return F (x) Tr / a, it emits at its output a maneuvering command to the DA module. This discriminates the action to be taken towards the actuator C or the actuator D as a function of the position noted by p16 and p16 'and the situation of the point R (FIG. 30) with respect to the desired position.

The importance and the speed of the action required from the actuators is proportional to the importance of the difference between CE and Cp16 + 16 '. This leads to producing a proportional, integral and derivative regulation. When the return of Cp16 + 16 'is equal to CE any action is canceled, the positioner is in equilibrium.30 The algorithm of the "Regulation" function is presented schematically in Figure 34. It describes the operations, conditions and actions necessary for the proper execution of the positioning of the butterfly valves.

It is assumed that the operator in charge of the operation of the tap will have chosen and loaded into the memory 29, the program 24 "regulation function" by the interface 20.

This program will be further parameterized by providing the dimension information of the valves, the type of control signal, digital or voltage or current and the calibration of the position sensors and the sensor of the physical quantity to be regulated.

Referring to FIG. 34 and considering the valve in an indeterminate position, the program receives an input command CE, this instruction is addressed to the reference comparator CpC. This comparator receives, on the other hand, a feedback of the transfer function of the process F (x) Tp which formats the signal CGs which is the image of the physical quantity to be adjusted. If the module Cpc finds a gap between the CE setpoint and the return F (x) Tp, it emits at its output a maneuver command to the module DA. This discriminates the action to be taken towards the actuator C or the actuator D as a function of the position observed by P16 and p16 'and the situation of the point R (FIG. 30) with respect to the desired position.

The importance and speed of the action requested from the actuators is proportional to the importance of the difference between CE and CGs. This leads to producing a proportional, integral and derivative regulation.

When the return CGs is equal to CE any action is canceled, the positioner is in equilibrium.

Claims (11)

REVENDICATIONS1. Valve device, comprising a main butterfly valve (A) (2), characterized by a butterfly valve (B) (12) mounted in the butterfly valve (2) of the main valve (A). 2. Device according to claim 1, characterized in that the butterfly (2) of the main valve is annular and the butterfly valve (12) of the secondary valve is mounted in the throttle hole (2) of the main valve. 3. Device according to claim 1 or 2, characterized in that the butterfly (2) of the main valve has a shaft (3) and a colinear pivoting shaft and the butterfly (12) of the valve (B) secondary has a shaft (13) and a pivot axis (14) colinear with those of the main valve (A). 4. Device according to claim 3, characterized in that the shaft (13) for actuating the butterfly valve (12) of the secondary valve is oriented towards the pivot axis (4) of the butterfly valve (2) of the main valve and the pivot pin (14) of the butterfly valve (2) of the secondary valve is oriented towards the shaft (3) for actuating the butterfly valve (12) of the main valve. 5. Device according to one of claims 3 or 4, characterized in that the axis (4) of pivoting of the throttle of the main valve is provided with a central recess in which the shaft (13) for actuating the throttle valve. Secondary faucet passes with sealing. 6. Device according to one of the preceding claims, including the main valve body, characterized in that the body of the main valve has two extensions (6, 6 ') diametrically opposed, one at the output of the shaft operating the main valve, the other at the output of the operating shaft of the secondary valve, each of the extensions (6, 6 ') being provided with a plate (7, 7') on which is fixed an actuator which actuates the respective operating shaft. 7. Device according to one of claims 2 to 6, characterized in that the outer diameter of the butterfly valve (2) of the secondary valve is 1 / 2.5 to 1/6 times the diameter of the butterfly valve (12) of the main valve . 8. Device according to one of claims 3 to 7, characterized by independent actuating devices of the shafts (3, 13) for actuating the butterflies (2, 12) of the valves (A, B) controlled by position sensors. angular position of the throttles (2, 12) and a torque sensor on the shaft (3) for operating the throttle valve (2) of the main valve (A), and the throttle valve control device (12) of the valve (B) secondary opens this butterfly (12) if said torque exceeds a prescribed value. 9. Device according to one of claims 3 to 7, characterized by a sensor of the pressure difference downstream and upstream of the device in a pipe in which the valve device is mounted or by a timer triggering while the device valve starts to open and / or to close and the throttle control device (12) of the main valve (A) opens this butterfly (2) only after a first prescribed duration, counted by the when the valve has been opened, and when the valve is closed, the throttle control device (12) of the secondary valve (B) does not open this valve (12). ) after a second prescribed time, counted by the timer, has elapsed, the first and second times being replaceable by first and second prescribed pressure differences. 10. A method for operating a valve device according to one of claims 1 to 7, characterized in that during the opening of the main valve, while it turned a positive angular value, the secondary valve is left in a negative angular position, for example at an angular position between 0 and 45 degrees, the secondary valve butterfly can in particular make an angle of 15 to 90 degrees with the main valve butterfly while the main valve is at a single opening angle between 30 and 75 degrees. 11. A method for operating a valve device according to one of claims 1 to 7, characterized in that the closing speed and / or opening of the secondary valve is changed during the opening and / or closing the main faucet.