RU2386069C2 - Monitoring of valve condition - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: group of inventions is provided for definition of valve condition, used in systems for preparation of foodstuff, beverage foods and drugs. Valve assembly contains valve (1), drive (2) and sensor (3) of drain. Casing (4) of valve contains the first and the second chambers (6, 8) of valve, connected to corresponding branches (10 and 12, 14 and 16) of valve. Chambers are connected by means of transition channel (18). Drive can install valve into one of three possible conditions. In the first "open" condition transition channel is open and the first and the second chambers of valve are communicated through transition channel. In the second "closed" condition transition channel is closed by the first and the second sealing (24, 26), which are located in corresponding areas of channel and it is sealed space between the first and the second chamber of valve and it is sealed the first chamber (28) against leakage in area which is a part of transition channel between two sealings. In the third condition of "cleaning" one of sealing is not located in working position which is for connection, correspondingly, either the first, or the second chamber of valve with the first chamber of leakage. The rest sealing is in working position. Flow-sensing element is connected to the first chamber of leakage for the purpose of generation of signal which indicates presence of leakage from the first leakage chamber. It is a method of condition monitoring of manageable above valve.

EFFECT: improvement of valve operation reliability.

16 cl, 2 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a device and method for monitoring the state of a hydraulic valve and, in particular, relates to monitoring unwanted flow through valve seals when the seals are in the operating position, or relates to confirming the desired flow through the seals when the seals are inoperative position.

State of the art

Typically, valves are used to control the flow of fluids in the manufacture and processing of a large number of products and materials. Seal leakage can result in losses in valve-driven streams or contamination of these streams. Thus, it is desirable to detect leakage in the seals at the initial stage of their operation before leakage through the seal reaches a certain level or contaminates the product. The absence of contamination is especially important in the preparation of products such as food, beverages and medicines, which are intended, for example, for people or animals.

Moreover, many products are manufactured or processed in batches, and between batches it is desirable or even necessary to clean equipment, such as tanks and lines. This is done in order to avoid mutual contamination of various products or to avoid the accumulation of mold, fungi, bacteria and other pathogenic microorganisms. In such situations, it is desirable to ensure that the necessary streams of cleaning or rinsing fluids pass through the processing unit.

US Pat. No. 4,655,253 describes a shut-off valve comprising a valve body with two chambers connected by an axial bore defined by valve seats. The valve body contains two parts that are capable of independent axial movement in the body. Each part contains a seal that interacts with one of the seats to block access between the camera and its associated channel. In an embodiment of the invention, a leak detection space is provided between the seats. The fluid passing through the saddles into this space exits through the channel, which allows a visual signal indicating leakage to be obtained and avoids mixing the corresponding fluids in the two chambers.

US Pat. No. 5,361,802 describes a valve block comprising metal electrodes. If the unit valve is leaky, a fluid leak connects the electrodes to the circuit and a signal is generated that is processed by the analyzer, which includes an alarm identifying the failed valve.

US Pat. No. 5,594,162 describes a gas leak detector configured to be installed around a valve control rod to monitor the leak of gaseous hydrocarbons from a valve.

US Pat. No. 5,616,829 describes a valve with a leak detector that monitors vibrations caused by leakage through the seats or valve packing / seal assembly. If a leak is detected in a closed valve, it moves further in the direction of closing, for example, until the leak disappears, and therefore the vibration.

Disclosure of invention

The objective of the invention is to provide a double seal valve with an improved valve condition monitoring system. Another object of the invention is to provide an improved method for monitoring the operating condition of a double-seal valve.

According to a first aspect, the invention, in a broad sense, is a valve device comprising:

(a) a valve comprising a housing with first and second chambers connected to respective valve nozzles, the chambers are connected via a transition channel, said valve can optionally be switched to the following states:

i) a first “open” state in which the transition channel is open and the first and second valve chambers communicate through the transition channel,

ii) a second “closed” state, in which the transition channel is closed by the first and second seals, which are located in respective places of the channel and seal the space between the first and second valve chambers and the first leakage chamber in the region that is part of the transition channel between the two seals, or

iii) a third “cleaning” state, in which one of the two seals is inoperative to connect either the first or second valve chamber to the first leak chamber, while the remaining seal is in the operating position,

(b) a valve actuator designed to selectively translate the valve into any of three states in response to appropriate control signals, and

(c) a flow sensor connected to the first leakage chamber and intended to generate an output signal of the flow sensor, which indicates the presence of leakage from the first leakage chamber, and a valve control unit that comprises at least one signal input port to which the output is transmitted the signal of the flow sensor, and the valve control unit is designed to:

generating at least one control signal for setting the valve in an appropriate state out of three possible,

responding to the output of the flow sensor and comparing the leakage level determined by the output signal of the flow sensor and a predetermined flow level from the first leakage chamber, which is associated with the selected valve state, and

generating an output signal of the control unit, which is generated based on the above comparison and is an indicator of the presence or absence of proper functioning of the valve or unwanted valve malfunction.

By means of an output signal from the control unit, a valve malfunction is determined, the valve being in the second “closed” state and the malfunction is a leak coming out of either the first or second valve chamber and passing through the first or second seal to the first leak chamber, respectively. Alternatively, or in addition to the one indicated by the output of the control unit, the proper functioning of the valve is determined when the valve is in the third “cleaning” state and the proper functioning of the valve is the flow through the seal in the non-working position from the corresponding valve chamber to the first chamber leaks.

The valve may include a third seal located between the first and second seals, the third seal being designed to seal the first leakage chamber relative to the connected valve chambers and the transition channel when the valve is in the first "open" state. Preferably, the valve malfunction is determined by the output of the control unit, the valve being in the first “open” state and the malfunction is a leak through the third seal into the first leak chamber from the communicating first and second valve chambers and the transition channel.

Preferably, the first and second seals are adapted to be mounted on the first and second valve elements, respectively; the first and second valve elements are arranged to independently move relative to the valve body to bring the valve into a selected state, the valve device comprising:

a second leak chamber located between the first valve member and the body;

a fourth seal designed to seal the first valve member relative to the valve body, a fourth seal is located between the first valve chamber and the second leakage chamber;

a third leakage chamber located between the second valve member and the valve body;

a fifth seal for sealing the second valve member relative to the valve body, the fifth seal being located between the second valve chamber and the third leakage chamber; and

the second and third leakage chambers connected to the flow sensor, the leakage passing through the fourth seal and entering the second leakage chamber or passing through the fifth seal and entering the third leakage chamber, is directed to the flow sensor, and leakage through the fourth or fifth seal is determined by output signal of the flow sensor.

Preferably, the valve malfunction is detected by the control unit output, the valve being in a first “open” state or a second “closed” state and the malfunction is a leak from the first valve chamber passing through the fourth seal to the second leak chamber, or leak from a second valve chamber passing through the fifth seal to a third leakage chamber.

A cylindrical hole can be made in the flow sensor and a pair of ring-shaped electrodes can be installed at a distance from each other along the axis and coaxially with respect to the electrically insulating wall of the cylindrical hole, and the flow sensor is connected to the first leakage chamber, and in case of leakage from the first leakage chamber passing through the cylindrical a hole across the electrodes, an electrically conductive jumper is formed between them.

According to a second aspect, the invention relates to a method for monitoring the state of a controllable valve, comprising a valve body with first and second valve chambers connected to respective valve nozzles, the chambers being connected by a transition channel, and said valve is configured to switch to the following states:

i) a first “open” state in which the transition channel is open, and the first and second valve chambers communicate via the transition channel,

ii) a second “closed” state, in which the transition channel is closed by the first and second seals, which are located in the corresponding places of the channel and are designed to seal the space between the first and second chambers of the valve, as well as the first leakage chamber in the area that is part of the transition channel between the two seals, or

iii) a third “cleaning” state in which one of the two seals is inoperative to connect either the first or second valve chamber to the first leak chamber, respectively, with the remaining seal in the operating position,

this method consists of the following steps:

(a) connecting the flow sensor to the first leakage chamber, wherein the flow sensor generates an output signal of the flow sensor to detect leakage from the first leakage chamber;

(b) receiving a valve control signal and selectively translating the valve into one of three possible states in response to the received control signal;

(c) comparing the leak detected by the output of the flow sensor and a predetermined flow level from the first leak chamber, which is associated with the selected valve state, and

(d) generating an output signal based on a comparison, which is an indicator of the presence or absence of proper valve operation or an undesired valve malfunction.

By means of the output signal generated in step (d) based on the comparison, the valve malfunction is determined when the valve is in the second “closed” state and the malfunction is due to a leak coming out of either the first or second valve chamber and passing through the first or second seal to the first leak chamber. Alternatively, or in addition to that indicated, by means of the output signal generated in step (d) based on the comparison, the proper functioning of the valve is determined, the valve being in the third “cleaning” state and the proper functioning of the valve is the flow through the seal, which is located in the idle position, from the corresponding valve chamber to the first leakage chamber.

Preferably, the valve contains a third seal located between the first and second seals, the third seal is designed to seal the first leakage chamber relative to the connected chambers of the valve and the transition channel, while the valve is in the first "open" state. By means of an output signal based on a comparison and generated by the valve control unit, the valve malfunction is determined when the valve is in the first “open” state and the malfunction is a leak through the third seal into the first leak chamber from the communicating first and second valve chambers and the transition channel .

It is preferable that the first and second seals are mounted respectively on the first and second valve elements, while the first and second valve elements are arranged to independently move relative to the valve body to bring the valve into a selected state, and in said valve:

a second leak chamber located between the first valve member and the body;

a fourth seal, designed to seal the first valve element relative to the valve body and installed between the first valve chamber and the second leakage chamber;

a third leakage chamber located between the second valve member and the valve body; and

a fifth seal for sealing the second valve member relative to the valve body and located between the second valve chamber and the third leakage chamber; moreover

the second and third leakage chambers are connected to the flow sensor, and the leakage passing through the fourth seal and entering the second leakage chamber or passing through the fifth seal and entering the third leakage chamber is directed to the flow sensor, while leakage is detected through the output signal of the flow sensor through fourth or fifth seals. By means of an output signal generated from the comparison, a valve malfunction is determined when the valve is in the first “open” state or the second “closed” state and the malfunction is due to leakage from the first valve chamber passing through the fourth seal to the second leakage chamber, or leakage from a second valve chamber passing through the fifth seal to a third leakage chamber.

A cylindrical hole is made in the flow sensor and a pair of ring-shaped electrodes is mounted at a distance from each other along the axis and coaxially with respect to the electrically insulating wall of the cylindrical hole, the flow sensor being connected to the first leakage chamber, so that a leak from the first leakage chamber passing through the cylindrical hole , across the electrodes, forms an electrically conductive jumper between them.

Brief Description of the Drawings

The present invention is described in detail with reference to preferred embodiments of the invention and with reference to the accompanying drawings, in which:

figure 1 is a cross section of a valve system corresponding to one embodiment of the invention,

figure 2 is a cross section of a flow sensor, which is used as part of the valve system of figure 1.

The implementation of the invention

In the drawings and in the description, the same or similar elements are denoted by the same reference numerals.

The valve system is shown and described in a situation where the valve and actuator are located in a preferred vertical position, it is clear that this particular version of the position is shown and described in general for convenience and clarity of description and the specified position does not limit the invention.

1 is a partial cross-sectional view of a valve system according to a preferred embodiment of the present invention. The valve system comprises a valve 1 and an associated valve actuator 2, which are shown with a cutout of the fourth part; the outside of the valve and actuator is shown on the left, and a transverse section through the plane passing through the longitudinal (i.e., vertical) axis of the valve and actuator is shown on the right. Figure 1 also schematically shows parts of the system that are not related to the valve and actuator.

The valve and actuator are usually symmetrical about the longitudinal axis, unless otherwise noted later. Sensor 3 is mounted on the lower end of the valve.

The housing 4 is made common to the valve and the actuator, the lower part of the housing contains two valve chambers: the first upper chamber 6 of the valve and the second lower chamber 8 of the valve. In the embodiment of the invention shown in FIG. 1, the upper valve chamber comprises a left nozzle 10 and a right nozzle 12, and the lower valve chamber contains a left nozzle 14 and a right nozzle 16. In another embodiment, the valve may contain a different number of nozzles, for example only one pipe in each chamber or only one pipe for both chambers, lower and upper, or each or both valve chambers may contain a larger number of pipes.

Two chambers 6, 8 of the valve are connected by a transition channel 18, which is made of a cylindrical shape and is coaxial with the valve body.

The valve comprises a first valve element 20 made in the form of a rod, and a second valve element 22 made in the form of a rod. The rods move along the axis of the valve body 4, while the second valve element 22 moves in general along the axis of the body, and the first valve element 20 is aligned with the upper part, but not with the top of the second rod.

The upper or first main seal 24 is located on the outer border of the first valve element 20 near its lower part. The lower or second main seal 26 is located on the outer boundary of the second valve element 22 in its middle part. Valve elements can be moved independently from each other in the axial direction of the valve body 4 in order to install two main seals in a cylindrical wall (working position) in the transition channel 18. The first leakage chamber 28 is located between the first and second main seals 24, 26, as will be described in detail described later.

The first valve element 20 moves in the upper pair of housing annular seals 30, 32, which are spaced apart and fit snugly against the inner wall of the upper portion of the valve body 4. These upper body seals 30, 32 provide a seal between the first moving valve member 20 and the valve body 4. The second leakage chamber 34 is bounded by a first stem, valve body 4 and two upper body seals 30, 32.

The second valve element 22 is moved in the lower pair of ring seals 36, 38 of the housing, which are located at a distance from each other and are snug against the inner wall of the lower part of the valve body 4. These lower body seals 36, 38 provide a seal between the second moving valve member 22 and the valve body 4. The third leakage chamber 40 is bounded by a second valve member, a valve body 4 and two lower body seals 36, 38.

The third main valve seal 42 is located in the lower end surface 44 of the first valve element 20. This third main valve seal may be pressed against the upward edge 46 of the second valve element 22 to close the outer boundary of the portion of the first leakage chamber 28 located between the end surface 44 and edge 46.

1, the valve is shown in a “closed” state in which both the first and second main valve seals 24, 26 are located in the transition channel 18 to isolate the first and second valve chambers 6, 8 from each other and from the first leakage chamber 28 which is sealed relative to the first valve chamber 6 by the first main valve seal 24 and which is sealed relative to the second valve chamber 8 by the second main valve seal 26. Since the first leakage chamber 28 is located between the two valve chambers, any leakage through any of the main seals 24, 26 enters the leakage chamber 28, which, due to its communication with the atmosphere, as will be described below, prevents mutual contamination of the valve chambers in " closed "state of the valve, which is shown in Fig.1. This “closed” state is the inoperative state of the valve.

At the upper end of the valve body 4, a valve actuator 2 is provided. In the embodiment of the invention shown in FIG. 1, the valve is actuated by applying pneumatic or hydraulic pressure to the control holes 50, 52, 54. The pressure supply is designed to control the axial movement of the two valve elements 20, 22, which will be described later. However, the valve can be actuated in other ways, for example by means of electric motors. Two valve stems are spring loaded with coil springs that are not shown. When releasing the pressure of the fluid applied to the control holes, these springs return the rods to an inoperative "closed" state.

When pressure is supplied to the first control hole 50, the first valve element 20 moves downward, which causes the third seal 42 located in the lower end face 44 of the first rod to be pressed against the upward edge 46 of the second valve element 22, and thus seals the outer boundary of the first leak chamber 28. Further downward movement of the first rod increases the pressure of the third seal onto the second rod and therefore moves the second rod downward, moving the second main seal 26 from the lower end of the transition channel 18. Further downward movement of the first rod moves the first main seal 24 downward through the transition channel, resulting in of which ultimately the first main seal 24 moves away from the lower end of the transition channel and, thus, the valve goes into an “open” state in which the first and second chambers 6, 8 inform can be reached by means of the transition channel 18. In this “open” state, the narrowed part 55 located near the lower end of the first valve element 20 covers the transition channel 18 and, therefore, provides free communication of the first and second valve chambers 6, 8.

As noted above, the valve returns to the inoperative “closed” state when the pressure applied to the first control hole 50 is released.

When pressure is supplied to the second control hole 52, the first valve element 20 moves upward, which causes the first main seal 24 to move away from the upper end of the transition channel 18 and, therefore, the first valve chamber 6 begins to communicate with the first leakage chamber 28. With the described movement, the second valve element 22 does not move from its idle position, so that the second main seal 26 remains located in the transition channel 18. In this first “cleaning” state, the cleaning fluid passing through the first valve chamber flows past the first main seal 24 and a third seal 42 and enters the first leak chamber 28. Thus, it is possible to rinse the first chamber 6 of the valve and the two seals 24, 42 with the cleaning fluid, while the cleaning fluid cannot enter the second chamber 8 of the valve due to the second main seal 26.

Similarly, when pressure is supplied to the third control hole 54, the second valve member 22 moves downward, causing the second main seal 26 to move away from the lower end of the transition channel 18 and, therefore, the second valve chamber 8 begins to communicate with the first leakage chamber 28 . With the described movement, the first valve element 20 does not move from its idle position, so that the first main seal 24 remains located in the transition channel 18. In this second “cleaning” state, the cleaning fluid flowing through the second valve chamber passes through the second main seal 26 and a third seal 42 and enters the first leak chamber 28. Thus, the second valve chamber 8 and the two seals 26, 42 can be flushed with a cleaning fluid, while the cleaning fluid cannot enter the first valve chamber 6 due to the first main seal 24.

The first leakage chamber 28 is open to the atmosphere due to the axially located drainage channel 56 located at the bottom of the second stem of the valve member 22. The lower end of this drainage channel ends with a first leakage hole 58. A leak entering the first leak chamber 28 (for example, through the first or second main seals 24, 26 when the valve is in the “closed” state, or past the third seal 42 when the valve is in the “open” state, or cleaning fluid, flowing past, respectively, the main seals 24, 26 and the third seal 42 in the first or second “cleaning” state), passes downward through the drainage channel 56 and is poured out of it through the first leakage hole 58.

Valve elements made in the form of valve stems and cavity of the valve body, in which the stems move, preferably in the cross section are made round. Similarly, seals are also round in cross section. In general, as noted above, the valve and actuator are generally axisymmetric about the longitudinal axis. Exceptions are valve nozzles 10, 12, 14 and 16 and control openings 50, 52, 54, which are usually aligned in their respective radial directions and which may contain threads and be aligned in a direction perpendicular to the longitudinal axis of the valve.

In the preferred embodiment of FIG. 1, the upper edge of the hollow funnel-shaped bell 60 comprises an outwardly directed flange through which the bell is secured around the lower end of the valve body 4 to the peripheral protrusion 62 by means of a collar 64. The bell is extended so that the first fits into it leak hole 58 at the lowest position of the second valve member 22, that is, when the valve is in the “open” state.

Figure 1 shows the appearance of the flow sensor 3 attached to the lower end of the socket 60. As best shown in figure 2, showing a cross section of the flow sensor, usually the flow sensor has a cylindrical shape and contains an axially aligned and cylindrical through hole 66.

The sensor 3 comprises an upper main sleeve 68 with an upper cylindrical groove 70, through which the sensor is attached to the cylindrical neck of the lower end of the socket 60. A headless screw 72 secures the sleeve relative to the neck. The upper electrically insulating ring-shaped sleeve 74 is installed in the lower cylindrical groove in the main sleeve 68. The annular conductive electrode 76 is inserted into the groove located at the lower end of the first insulating sleeve 74. The lower electrically-insulating ring-shaped sleeve 78 is installed in the lower end of the ring-shaped electrode. An annular mounting plate 80 surrounds and is located on the lower insulating sleeve. On the circuit board are electronic components, one of which is a light emitting diode 82, the indication of which facilitates the solution of the problem of finding the location of the fault. In a preferred design, not shown here, there are three LEDs located at the same distance from each other, spreading light in the direction of 360 ° from the location of the sensor.

A cylindrical housing 84 made of stainless steel is inserted into the lower end of the main sleeve and surrounds and therefore covers the insulating sleeves, electrode, circuit board and LEDs. The voids between the electrodes and the housing are filled with an electrically insulating sealing material 86. The connecting device 88 is installed in a cylindrical housing 84 and is designed to connect the sensor to external devices for supplying power to the sensor and for transmitting the sensor output signal to the remote system. The innermost walls of the main coupling 68, the upper and lower insulating sleeves and the electrode are cylindrical and have substantially the same diameter. Together, these walls form a cylindrical through hole 66.

The main coupling, headless screw, electrode and housing are preferably made of stainless steel, and in a preferred embodiment SS304, the main coupling, headless screw and electrode are made of stainless steel, and in the preferred embodiment SS316, the housing is made of stainless steel. Alternatively, they can be made of any other material suitable for use with working and cleaning fluids circulating in the valve.

The upper and lower insulating sleeves are preferably made of a material that resists wetting by the working and cleaning fluids circulating in the valve. In a preferred embodiment, the insulating sleeves are made of a chemically inert and hydrophobic material, preferably polytetrafluoroethylene (PTFE). The use of PTFE for insulating sleeves reduces the sensitivity of the sensor in the presence of humidity and the absence of flow through the sensor.

With sufficient fluid flow down the wall of the through hole 66, it provides an electrically conductive jumper between the main coupling, which acts as a single sensor electrode, and the ring-shaped electrode, the electronic circuit initiates an output signal on the connecting device 88, showing this flow. Also, the light emitting diode 82 provides an indication of the flux.

Thus, the sensor initiates a signal in response to the presence of a flow starting in the first leakage chamber and passing through the drainage channel 56, the first leakage hole 58, the bell 60, and the hole 66 in the flow sensor.

In the socket 60, drainage holes 89 are provided for removing excess flow that cannot easily pass through the hole 66 of the flow sensor. It should be noted that the fluid passing through the valve may be a gas or a mixture of gas and liquid; this may lead to a flow of liquid through the sensor. For example, when steam is used to clean the valve, the flow through the sensor may be condensate, which is a liquid.

The output of the sensor is transmitted from the connecting device 88 through the signal bus 90 to the external port of the valve control system 91 and monitor its status. The valve control and monitoring system initiates control signals in the control buses 92, 94, 96, respectively, for the control openings 50, 52, 54 of the valve actuator 2. These control signals are necessary to set valve 1 in one or another state. In a typical application, the valve control and condition monitoring system preferably comprises a programmable logic control device (PLEU), a control and data acquisition system (SCSD), or any computer-based or microprocessor-based control and monitoring system.

The valve control and monitoring system 91 compares the sensor output and the control signal sample that was sent to control the valve actuator 2 in order to put the valve 1 into the selected state. The valve control and monitoring system compares the fluid flow through the sensor 3, the specified flow is represented by the output of the sensor, and the predetermined desired level of flow from the first leakage chamber 28 through the opening 58 associated with the selected valve state. Further, the valve control and monitoring system generates an output signal that is a consequence of the above comparison and indicates the presence or absence of proper valve operation or an undesired valve malfunction. The output can be transmitted to a remote system to inform the operator of the presence or absence of proper valve operation or an undesired valve malfunction. Alternatively, when the valve is part of a process plant, the process plant control system may respond to an output signal indicating the presence or absence of proper valve operation or an undesired valve malfunction.

In the first example, when the valve is in the “open” state, the predetermined desired level of flow associated with this state from the first leakage chamber 28 to the sensor 3 is zero, which corresponds to the expected situation when there is no leakage through the third valve seal 42. If the sensor signal indicates the presence of flow in the case when the valve is in this state, the valve control and monitoring system generates an output signal indicating a valve malfunction. On the contrary, if the sensor signal does not show the presence of flow in the case when the valve is in this state, the valve control and monitoring system generates an output signal confirming the proper functioning of the valve.

In the second example, when the valve is in an inoperative "closed" state, the predetermined desired level of the flow associated with this state from the first leakage chamber 28 to the sensor 3 is zero, which corresponds to the expected situation when there is no leakage through the main valve seals 24, 26. If the sensor signal indicates the presence of flow in the case when the valve is in this state, that is, there is a leak from either the first or second valve chambers 6, 8 passing through the first or second main seals 24, 26 and entering the first leak chamber 28 then the valve control and monitoring system 91 generates an output signal indicating a valve malfunction. On the contrary, if the sensor signal does not show the presence of flow in the case when the valve is in this state, the valve control and monitoring system generates an output signal confirming the proper functioning of the valve.

In the third example, when the valve is in one of the “cleaning” states, the predetermined desired level of flow associated with this state from the first leakage chamber 28 to the sensor 3 is significant, which corresponds to the expected situation when the cleaning fluid passes through one of the valve chambers past the main seal in the idle position. If the sensor signal indicates the presence of flow when the valve is in this state, the valve control and monitoring system generates an output signal confirming the proper functioning of the valve. On the contrary, if the sensor signal does not show the presence of flow in the case when the valve is in this state, then the valve control and monitoring system generates an output signal indicating the absence of the expected flow of the cleaning fluid, i.e., the valve malfunction.

The leakage range detected by the described system and the flow monitoring provided by the described system can be easily increased, which will be described below. A fluid conduit 100 connected to a leakage hole 102 that leads from the second leakage chamber 34 is connected to a hole 104 leading to the inside of the socket 60. Thus, the leakage passing through the upper seal 30 of the body into the second leakage chamber 34 into the bell 60 and therefore goes down to the sensor 3. Similarly, the fluid conduit 106 connected to the leak hole 108, which leads from the third leak chamber 40, is connected to the hole 104 leading to the inside of the bell 60. Thus, the leak , past coming through the lower seal 36 of the housing into the third leakage chamber 40, it enters the socket 60 and, therefore, goes down to the sensor 3. Pipelines 100, 106 can be connected and, thus, can lead to a common hole 104 open to the inside of the socket as described above and shown in FIG. 1, or the pipelines may individually be connected to the corresponding openings. Thanks to these additional pipelines, the sensor 3 detects leaks starting either in the first or second chamber 6, 8 and passing into the second and third leakage chambers 34, 40, respectively.

It should be noted that monitoring the valve condition described above can provide an indication of many valve conditions using only one flow sensor. It should also be noted that, for convenience, in FIG. 1, the hole 104 is shown directly above one of the drainage holes 89. However, in practice, the drainage hole is not located directly below the hole 104, so that the liquid flow entering the socket through the hole 104 flows down the inner wall of the socket and then through the hole 66 of the sensor 3.

Although there may be some uncertainty about the cause of the flow in the sensor for any valve condition, in at least some cases, you can wait for the valve to transition to another state or other states and relate the presence of flow in the sensor to some state or conditions. In some cases, for specific valve conditions, any uncertainty can be overcome as follows: by associating the detected flow in the sensor with the known presence of fluid and its pressure in specific valve chambers.

Even with some uncertainty, this system is useful because it can be used to confirm the proper flow of cleaning fluids when the valve is in the “clean” state, and to confirm that there are no leaks through the seals in the operating position when the valve is in the “open” or "Closed" state. In this way, an early warning of seal leaks or system malfunctions can be obtained. Moreover, in contrast to the known visual warning methods for the valve (for example, based on the flow exit from the first leakage hole 58), the warning provided by the valve system described above and shown in FIG. 1 can be transmitted to the remote monitoring system and can be used to control a process using a valve system.

It is clear that the invention is not limited to the specific valve design described above, which is considered only as an example of one preferred embodiment of the invention. Without departing from the scope of the invention, the combined use of a flow sensor and a double seal valve can be used with other double seal valve designs. For example, the invention can be used in a double-seal valve in which both valve stems are actuated from below. Such valves are commonly used to control the inlet and / or outlet flows at the bottom of tanks or similar tanks.

One application of a preferred embodiment of the invention is associated with hygienic mixing-protected (i.e. double-sealed) valves used in food processing, for example in dairy processing, when early warning of seal leaks and confirmation of proper cleaning is very important to eliminate the risk of mixing products food and cleaning fluids or eliminating the risk of bacteria or other pathogens remaining in the valve.

Although the preferred embodiment of the invention described herein uses a conductivity-based sensor, other sensors may be used to provide an indication of the presence or absence of flow. Such sensors may be preferred in cases where the fluid flow has insufficient electrical conductivity and the sensor described above is not able to easily detect the presence of flow. For example, an alternative sensor may be based on the use of electric capacitance when the transmitted stream serves as the dielectric between the capacitor plates in the sensor.

The term “comprising”, as used in this description and the claims, means “at least partially consisting of”, that is, when interpreting the sentences of this description and the claims using this term, all the elements to which this term refers in the sentence must be present, but other elements may also be present.

Claims (16)

1. The valve device comprising a valve with a valve body, as well as with the first and second valve chambers connected to the corresponding valve nozzles, and the chambers are connected by a transition channel, while the valve is configured to switch to the following states:
i) a first “open” state in which the transition channel is open and the first and second valve chambers communicate via the transition channel,
ii) a second “closed” state, in which the transition channel is closed by the first and second seals, which are located in the corresponding places of the channel and are designed to seal the space between the first and second chambers of the valve, as well as the first leakage chamber in the area that is part of the transition channel between the two seals, or
iii) a third “cleaning” state, in which one of the two seals is inoperative to connect either the first or second valve chamber to the first leak chamber, while the remaining seal is in the operating position,
and a valve actuator for selectively translating the valve into any of three states in response to respective control signals, and a flow sensor coupled to the first leakage chamber and for generating an output of the flow sensor that indicates the presence of leakage from the first leakage chamber, and a valve control unit with at least one signal input port to which the output signal of the flow sensor is transmitted, wherein the valve control unit is designed to generate at least one about a control signal for setting the valve into an appropriate state out of three possible, as well as responding to the output signal of the flow sensor and comparing the leakage level determined by the output signal of the flow sensor and a predetermined flow level from the first leakage chamber, which is associated with the selected valve state, and generating an output signal of the control unit, which is generated based on the above comparison and is an indicator of the presence or absence of proper functioning of the valve or Valve malfunction. 2. The valve device according to claim 1, in which the valve malfunction is determined by the output of the control unit, the valve being in the second “closed” state and the malfunction is a leak coming out of either the first or second valve chamber and passing accordingly through the first or second seal to the first leak chamber. 3. The valve device according to claim 1, in which the proper operation of the valve is determined by the output of the control unit when the valve is in the third “cleaning” state and the proper functioning of the valve is the flow through the seal in the idle position from the corresponding valve chamber into the first leak chamber. 4. The valve device according to claim 1, in which the valve comprises a third seal located between the first and second seals, the third seal being designed to seal the first leakage chamber relative to the connected valve chambers and the transition channel when the valve is in the first "open "Condition. 5. The valve device according to claim 4, in which the valve malfunction is determined by the output of the control unit, the valve being in the first “open” state and the malfunction is a leak through the third seal into the first leak chamber from the communicating first and second valve chambers and transition channel. 6. The valve device according to claim 1, in which the first and second seals are made to be mounted respectively on the first and second valve elements, the first and second valve elements are arranged to independently move relative to the valve body to bring the valve into a selected state, the valve device further comprises a second leakage chamber located between the first valve member and the housing, and a fourth seal for sealing the first valve member relative to with respect to the valve body, wherein a fourth seal is located between the first valve chamber and the second leakage chamber, and a third leakage chamber located between the second valve element and the valve body, and a fifth seal for sealing the second valve element relative to the valve body, the fifth a seal is located between the second valve chamber and the third leakage chamber; wherein the second and third leakage chambers are connected to the flow sensor, wherein the leakage passing through the fourth seal and entering the second leakage chamber or passing through the fifth seal and entering the third leakage chamber is directed to the flow sensor, and the leakage through the fourth or fifth seal is determined by output signal of the flow sensor. 7. The valve device according to claim 6, in which the valve malfunction is determined by the output of the control unit, the valve being in the first "open" state or the second "closed" state and the malfunction is a leak from the first valve chamber passing through the fourth the seal in the second leakage chamber, or leakage from the second valve chamber passing through the fifth seal into the third leakage chamber. 8. The valve device according to claim 1, in which a cylindrical hole is made in the flow sensor and a pair of ring-shaped electrodes is installed at a distance from each other along the axis and coaxially with respect to the insulating wall of the cylindrical hole, and the flow sensor is connected to the first leakage chamber, wherein leakage from the first leakage chamber passing through a cylindrical hole across the electrodes, an electrically conductive jumper is formed between them. 9. A method for monitoring the state of a controllable valve, comprising a valve body with first and second valve chambers connected to respective valve nozzles, wherein the chambers are connected by a transition channel, and said valve is configured to switch to the following states:
i) a first “open” state in which the transition channel is open and the first and second valve chambers communicate via the transition channel,
ii) a second “closed” state, in which the transition channel is closed by the first and second seals, which are located in the corresponding places of the channel and are designed to seal the space between the first and second chambers of the valve, as well as the first leakage chamber in the area that is part of the transition channel between the two seals, or
iii) a third “cleaning” state, in which one of the two seals is inoperative for connecting either the first or second valve chamber to the first leakage chamber, while the remaining seal is in the operating position, with the following steps being performed in said method :
(a) connecting the flow sensor to the first leakage chamber, wherein the flow sensor generates an output signal of the flow sensor to detect leakage from the first leakage chamber;
(b) receiving a valve control signal and selectively transferring the valve to one of three possible states in response to the received control signal;
(c) comparing the leakage detected by the output of the flow sensor with a predetermined flow level from the first leakage chamber, which is associated with the selected valve state, and
(d) generate an output signal based on a comparison, which is an indicator of the presence or absence of proper functioning of the valve or unwanted malfunction of the valve. 10. The monitoring method according to claim 9, in which, using the output signal generated in step (d) based on the comparison, the valve malfunction is determined, the valve being in the second “closed” state and the malfunction is the presence of a leak coming from or from the first or from a second valve chamber and passing respectively through the first or second seal into the first leak chamber. 11. The monitoring method according to claim 9, in which by means of the output signal generated in step (d) based on the comparison, the proper functioning of the valve is determined, the valve being in the third “cleaning” state and the proper functioning of the valve is the flow through the seal which is in the idle position, from the corresponding valve chamber to the first leakage chamber. 12. The monitoring method according to claim 9, in which the valve is equipped with a third seal located between the first and second seals, the third seal being designed to seal the first leakage chamber relative to the connected valve chambers and the transition channel, the valve being in the first “open” "Condition. 13. The monitoring method according to item 12, in which through the output signal based on the comparison and generated by the valve control unit, the valve malfunction is determined, the valve is in the first "open" state and the malfunction is a leak through the third seal into the first chamber leaks from the communicating first and second chambers of the valve and the transition channel. 14. The monitoring method according to claim 9, in which the first and second seals are mounted respectively on the first and second valve elements, wherein the first and second valve elements are independently movable relative to the valve body to bring the valve into a selected state, and in said valve perform a second leakage chamber located between the first valve member and the body, a fourth seal designed to seal the first valve member relative to the valve body, mounted between the first Amer valve leaks and the second chamber, the third diversion chamber located between said second valve element and the valve body; and a fifth seal for sealing the second valve member relative to the valve body, which is located between the second valve chamber and the third leakage chamber, the second and third leakage chambers being connected to the flow sensor, and the leakage passing through the fourth seal and entering the second leakage chamber or passing through the fifth seal and entering the third leakage chamber, is directed to the flow sensor, while leakage through the fourth or Toe seal. 15. The monitoring method according to 14, in which through the output signal generated on the basis of comparison, determine the malfunction of the valve when the valve is in the first "open" state or the second "closed" state and the malfunction is a leak from the first valve chamber, passing through the fourth seal into the second leakage chamber, or leakage from the second valve chamber, passing through the fifth seal into the third leakage chamber. 16. The monitoring method according to claim 9, in which a cylindrical hole is made in the flow sensor and a pair of ring-shaped electrodes is mounted at a distance from each other along the axis and coaxially with respect to the insulating wall of the cylindrical hole, the flow sensor being connected to the first leakage chamber, in case of leakage from the first leakage chamber passing through a cylindrical hole across the electrodes, an electrically conductive jumper is formed between them.

Images