Control system for a valve or pressure regulator for gas or gas installations suitable for operation in high explosion risk environments

Abstract

A control system (10) for controlling a valve or a pressure regulator for combustible gas or explosive gas systems, comprising a valve body (51), an intervention member (52) defined within said valve body (51), a threaded element (53) for controlling the intervention member (52), said threaded element (53) having a operating head (54), the threaded element (53) defines a manoeuvring axis (XI) with respect to which the same threaded element is screwable or unscrewable with respect to a counter-threaded hole defined on the valve body (51) to control the intervention member (52), a motor assembly (11), a rotatable spool (12) configured to couple with the operating head (54), and means for transmitting rotation (40) from the motor assembly (11) to the spool (12). The means of transmitting the rotation (40) from the motor unit (11) to the slider (12) comprise a driving rotor (16) and a driven rotor (21) both of magnet type, the driven rotor (21) being arranged coaxial to said driving rotor (16) and being arranged to surround said driving rotor (16) with clearance.

Description

[0001] CONTROL SYSTEM FOR A VALVE OR PRESSURE REGULATOR FOR GAS OR GAS INSTALLATIONS SUITABLE FOR OPERATION IN HIGH EXPLOSION RISK ENVIRONMENTS

[0002] The present invention concerns a control system for a valve or a pressure regulator control for combustible gas or gas installations suitable for operation in environments with a high explosion risk.

[0003] In particular, it is an object of the present invention to provide a control device that can be applied to pre-existing valves, pressure regulators, pilot devices and the like of a gas distribution system.

[0004] Operationally, a valve is understood in this text to mean a device capable of modulating the gas flow rate in a conduit with which such a valve is associated and / or regulating a pressure difference of the gas flowing through the valve between an upstream and downstream branch thereof.

[0005] Structurally, a valve is generally understood to be a device configured to regulate the opening of a passage section for a gas between the upstream and downstream branches.

[0006] This invention refers, in particular, to a drive apparatus configured to meet the requirements of suitability, according to ATEX Directive 2014 / 34 / EU, to operate within zones classified as ATEX 0, 1 or 2, according to Directive 99 / 92 / EC.

[0007] Notoriously, manually actuated valves are used in such areas, the adjustment of which is carried out by acting on a screw whose head protrudes outside the valve body. There is a known prejudice against the use of electromechanical actuators due to the potential risk of gas escaping into the environment in which the actuator-operated valve is hosted. In order to overcome the imprecision and inefficiency of a manual actuation of such valves, an actuation apparatus comprising a coupling organ having a shaped seat capable of coupling slidingly with the screw head of a valve is disclosed in patent document EP2818961 , in the name of the same applicant. This apparatus is easy to apply to pre-existing installations without significant modifications to them. In addition, it is equipped with a motor for driving the rotation of the coupling organ that is suitable for operating in explosion- hazardous areas, and in particular suitable for operating in ATEX Zones 1 and 2.

[0008] As much as this apparatus is appreciated, it proved perfectible.

[0009] In particular, this applicant has identified the need to increase the safety of the drive by sealing the electrically powered portions of the motor from the environment in which the drive apparatus is installed, while maintaining the functionality and efficiency of the drive apparatus.

[0010] Another detriment to the use of electromechanical actuators is the fact that the electric motor-gearbox could lead to dangerous situations if an explosive fluid were to leak through the sealing systems, typically one or more annular bodies made of plastic or another equivalent material, which affect the motor's rotating shaft, into the interior of the electric motor itself where the windings and control electronics are located.

[0011] There is also a great need in the industry for an automatic control of the valve opening condition, or control of the position of another control element, that is both precise and reliable.

[0012] The problem underlying the present invention is especially to meet these requirements. It is therefore the task of the present invention to make available a control system for a control of valve, or of a pressure regulator, for combustible or explosive gas installations, which prevents or limits the need for calibration of the valve or the valve to which it is coupled and which ensures lasting reliability of the valve's setting accuracy as well as its control.

[0013] Within the scope of this task, one purpose of the present invention is to propose a control system configured to meet the requirements of suitability, according to the ATEX Directive 2014 / 34 / EU, to operate within zones classified as ATEX 0, 1 or 2, according to Directive 99 / 92 / EC. Another purpose of the present invention is to develop a control system in which electrically current-carried or energized parts are completely safe from the risk of contact with a flammable or explosive fluid from which the control system itself can be invested.

[0014] Another purpose of the present invention is to develop a control system that allows the operating condition of the valve, or pilot device, or associated pressure regulator to be accurately detected.

[0015] Still another purpose of the present invention is to propose a control system that allows the degree of opening, or closing, of such valves to be regulated with precision and lasting reliability.

[0016] This task, as well as these and other purposes that will better appear below, are achieved by a control system for a valve control or pressure regulator for combustible or explosive gas systems according to the attached independent claim.

[0017] Detailed characteristics of a control system for a valve control or pressure regulator for combustible or explosive gas systems according to the invention are given in the dependent claims which are incorporated herein by reference. Further features and advantages of the invention result more from the description of a preferred, but not exclusive, embodiment of a control system for a valve control or pressure regulator for combustible gas or explosive gas systems, according to the invention, illustrated by way of illustration and not limitation in the accompanying drawings, wherein:

[0018] - Figure 1 illustrates a perspective view of an application of a control system according to the invention;

[0019] - Figure 2 represents a partially exploded perspective view of the system according to the invention;

[0020] - Figure 3 represents a schematic cross-sectional side view of the control system according to the invention;

[0021] - Figure 4 represents a detail of figure 3.

[0022] With particular reference to the figures mentioned, a control system for controlling a valve or a pressure regulator for combustible or explosive gas installations is referred to as a whole as number 10.

[0023] This control system 10 includes:

[0024] - a valve body 51 ; said valve body 51 is intended to be connected to two sections of a pipeline; said valve body 51 comprises an internal passageway configured to connect the two sections of pipeline; said internal passageway is not illustrated for simplicity of presentation;

[0025] - an intervention member 52 defined inside said valve body 51 ; said intervention member 52 is configured to act on a fluid within said valve body 51 ,

[0026] - a threaded element 53, clearly visible in Figures 2 and 3, for controlling said intervention member 52; said threaded element 53 extends from the valve body 51 ; said threaded element 53 has an operating head 54; said threaded element 53 defines an operating axis X1 with respect to which said threaded element 53 is screwable or unscrewable with respect to a counterthreaded hole defined on said valve body 51 for controlling the intervention member 52; By way of example, the valve body 51 may be defined by the body of a pilot device for gas pressure regulation systems in a gas distribution system, or a pressure regulator, wherein said pilot device and said pressure regulator are intended to be of a type known in themselves;

[0027] - a motor unit 11 ;

[0028] - a rotatable slider 12 configured to couple with the operating head 54, as shown in the section of figure 3, to rotate the operating head 54 around said operating axis X1 ,

[0029] - rotation transmission means 40 for transmitting the rotation from the motor unit 11 to the rotatable slider 12,

[0030] - means 60 configured to allow translation, during rotation, of said rotatable slider 12 along said operating axis X1.

[0031] The peculiarity of the present invention lies in the fact that the motor unit 11 comprises, as schematically exemplified in Figures 3 and 4:

[0032] - an electric motor 14 having a drive shaft 15,

[0033] - a driving rotor 16, of magnet type, comprising an outer perimeter ring of first permanent magnets 17; this driving rotor 16 is fixed to the motor shaft 15, a sealed box body 18 inside of which an electrical insulation chamber 19, in which the electric motor 14 is housed, and a rotation chamber 20, inside of which said driving rotor 16 rotates, are defined.

[0034] The rotation transmission means for transmitting rotation from the motor unit 11 to the slider 12 comprise a driven rotor 21 of magnet type, comprising in turn an inner perimeter ring of second permanent magnets 22, said driven rotor 21 being arranged in a coaxial position, i.e. coaxially, to said driving rotor 16, and being arranged to surround with clearance the driving rotor 16.

[0035] The first permanent magnets 17 of the driving rotor 16 are arranged angularly equidistant.

[0036] The first permanent magnets 17 of the driving rotor 16 are arranged with alternating polarity, so a first permanent magnet 17 of positive polarity is arranged between two first permanent magnets 17 of negative polarity.

[0037] The second permanent magnets 22 of the driven rotor 21 are arranged angularly equidistant.

[0038] In particular, the second permanent magnets 22 are angularly equidistant at the same spacing angle as the first permanent magnets 17.

[0039] The second permanent magnets 22 of the driven rotor 21 are arranged with alternating polarity, so a second permanent magnet 22 of positive polarity is arranged between two second permanent magnets 22 of negative polarity.

[0040] The first permanent magnets 17 are essentially parallelepiped in shape.

[0041] The first permanent magnets 17 are positioned essentially tangentially to a cylindrical surface, the cylindricity of which refers to the axis of rotation of the driving rotor 16 of which they are a part.

[0042] The second permanent magnets 22 are also substantially parallelepiped in shape.

[0043] The second permanent magnets 22 are essentially positioned tangentially to a cylindrical surface, the cylindricity of which refers to the axis of rotation of the driven rotor 21 of which they are part. The first permanent magnets 17 and the second permanent magnets 22 are arranged in such a way that at each rotation having the value of the spacing angle as identified above, each first permanent magnet 17 faces a second permanent magnet 22.

[0044] The first magnets 17 of the driving rotor 16 having a first polarity drive the second magnets 22 of the driven rotor 21 having the opposite second polarity into rotation.

[0045] The arrangement of the magnets is such that each first magnet always faces a second magnet with opposite polarity.

[0046] The rotation chamber 20 is defined by a continuous tumbler-shaped portion 23 of the sealed box body 18.

[0047] This continuous tumbler-shaped portion 23 is at least partly interposed between the driving rotor 16 and the driven rotor 21 .

[0048] This continuous tumbler-shaped portion 23 is therefore positioned in the gap, i.e. the space, between the driving rotor 16 and the driven rotor 21 , as can be seen in figure 4.

[0049] As an application example of the control system 10 according to the invention, a generic pressure regulator R is shown in figure 1 , which is to be understood as a known type per se.

[0050] Such a pressure regulator R is governed for example, but not exclusively, by a pilot device, or other regulating and / or setting component, comprising a valve body 51 .

[0051] Due to the magnetic forces between the first magnets 17 and the second magnets 22, the driven rotor 21 is pulled into rotation by the driving rotor 16 without any contact between the two rotors. In this way, the driving rotor 16 is completely enclosed in the sealed box body 18, and any gas reaching the driven rotor 21 could in no way reach the electric motor 14, which is also inside the sealed box body 18.

[0052] The electrical isolation chamber 19 and the rotation chamber 20 are separated by an annular sealing wall 25.

[0053] This annular sealing wall 25 is fixed inside the sealed box body 18.

[0054] This annular sealing wall 25 has a central bore 25a through which the drive shaft 15 passes.

[0055] The contact zones 26 between the annular sealing wall 25 and the inner surface of the sealed box body 18 and the contact zones 27 between the drive shaft 15 and the inner surface of the central bore are therefore never lapped by gas, which gas is therefore prevented from reaching the electric motor 14.

[0056] In particular, the sealed box body 18 is filled with synthetic resin 28.

[0057] The filling with synthetic resin prevents an explosive atmosphere from coming into contact with the electric motor 14.

[0058] Preferably, a mother board 30 for controlling and managing the electric motor 14 is also located inside the sealed box body 18.

[0059] The motherboard 30 is also preferably embedded in synthetic resin 28.

[0060] The sealed box body 18 is also intended to be capable of being filled with a different but technically equivalent sealing material to synthetic resin.

[0061] The sealed box body 18 also comprises a side chamber 18a.

[0062] In contrast, the side chamber 18a of the sealed box body 18 is free of synthetic resin 28.

[0063] In the side chamber 18a there is an electronic connection board 30a.

[0064] Motherboard 30 contains the system intelligence and also contains the entire power section, which is why it is resined.

[0065] Connection board 30a contains connectors for sensors and communication. Connection board 30a is not resined and is therefore physically located in a separate compartment from the motherboard.

[0066] Motherboard 30 and connection board 30a communicate with each other via a flat cable that is permanently immersed in resin on the side of the motherboard; this flat cable is not illustrated for simplicity's sake, and is obviously to be understood as a known type.

[0067] The driven rotor 21 is fixed axially to a driven shaft 32 at the input of the rotation transmission means.

[0068] These means of transmitting rotation are understood to include a cascade of gears, or a belt device, or a mixed belt - gear system, or another technically equivalent means of transmitting rotation.

[0069] In particular, for use in a Zone 0 according to the ATEX standard, the means of transmission of rotation are of the gear type, as this standard prohibits the use of belts.

[0070] The group of rotational drives is collectively referred to by the number 40.

[0071] The sealed box body 18 has an access opening 41 .

[0072] In particular, this access opening 41 is configured to be such only during production and assembly; once synthetic resin 28 has been poured, access opening 41 no longer exists in practice; this peculiar sealing allows the requirements of the above-mentioned ATEX standard to be met.

[0073] This access opening 41 allows the introduction into the sealed box body 18 of the driving rotor 16, the sealing ring wall 25 and the electric motor 14, the electronic board 30 as well as the introduction of the synthetic resin 28. The sealed box body 18 consists essentially of a single plastic body, or alternatively of two plastic parts joined to seal each other.

[0074] The sealed box body 18 has a single opening consisting of access opening 41 .

[0075] The sealed box body 18 has an electrical connection cover 42 through which the power and / or signal transmission cables for the circuit board 30 and the electric motor 14 enter the sealed box body 18.

[0076] The electrical connection cover 42 is also made of plastic.

[0077] Preferably, this electrical connection cover 42 is made of a plastic material capable of ensuring an IP54 degree of protection against the elements.

[0078] By way of illustration, but not limitation of the invention, means 60 configured to allow translation, during rotation, of said rotatable slider 12 along said operating axis X1 , comprise an actuator member 61 connected to the rotation means 40 so as to be actuated in rotation about said operating axis X1 .

[0079] The actuating organ 61 is brought into rotation by the rotation means 40.

[0080] Actuating organ 61 and rotatable slider 12 are configured to mutually couple in a sliding manner in a direction parallel to the operating axis X1 and to simultaneously rotate around it.

[0081] The actuating organ 61 comprises a bell element 62 attached to a hollow rotating shaft 63.

[0082] In other words, the slider 12 and the actuating organ 61 are formed in such a way that the slider 12 can slide with respect to the actuating organ 61 along the operating axis X1. The actuating organ 61 pulls the slider 12 with itself in rotation, around the operating axis X1 , and leaves the same slider 12 free to slide along the operating axis X1 .

[0083] Preferably, but not exclusively, the control system 10 according to the present invention also comprises a sensing device 70 which is capable of sensing an operating position of the slider 12 along the operating axis X1 with respect to a positional reference of the control system 10.

[0084] For example, the operating position of the slider 12 can be determined on the basis of the stress exerted on a load cell 71 which on one side is fixed to a supporting structural element 72 and on the opposite side receives a thrust from a pusher component 73 which in turn is pushed by an intermediate component 74 interposed between the slider 12 and the pusher component 73 itself.

[0085] For example, the intermediate component 74 is a helical thrust spring coaxially arranged within the hollow rotating shaft 63.

[0086] The slider 12 is supported on a guide shaft 75 also located in the actuating organ 61 , this guide shaft 75 being coaxial to the hollow rotating shaft 63.

[0087] Slider 12 has at least one radial relief, not shown, coupled in a longitudinal slot 62a, shown in figure 3, defined on the bell-shaped element 62.

[0088] The rotation of the hollow rotating shaft 63 causes the rotation of the bellshaped element 62, which, by means of its longitudinal slot 62a coupled with the radial relief of the slider 12, brings the slider 12 itself into rotation.

[0089] The spool 12 rotating determines the corresponding rotation of the threaded element 53, and is free to follow the axial displacement along the operating axis X1 of the same threaded element 53 unscrewing or screwing with respect to the valve body 51 .

[0090] Slider 12 can translate along the X1 axis as it is free in relation to the hollow rotating shaft 63 and is not bound to it.

[0091] The invention thus accomplishes its task and purpose.

[0092] In particular, the present invention has developed a control system that is completely safe with respect to what is required by national and international regulations.

[0093] In addition, the invention provides a control system in which electrically current- carried or energized parts are completely safe from the risk of contact with a flammable or explosive fluid from which the control system itself could be affected.

[0094] Furthermore, with the present invention, a control system has been developed that allows the operating condition of the valve, or pilot device, or associated pressure regulator to be accurately detected.

[0095] Furthermore, it is understood, therefore, how the implementation of the present invention makes it possible to avoid calibration or adjustment of the actuating apparatus and / or the valve on which it is installed in order to ensure precise adjustment and lasting reliability.

[0096] A control system according to the present invention also allows the degree of opening, or closing, of the valve on which it is installed to be regulated precisely and reliably without the use of skilled personnel.

[0097] The invention thus conceived is susceptible to numerous modifications and variations, all of which fall within the scope of protection of the attached claims.

[0098] In addition, all details may be replaced by other technically equivalent elements.

[0099] In practice, the materials used, as well as the contingent shapes and dimensions, may be varied according to contingent requirements and the state of the art.

[0100] Where the construction characteristics and techniques mentioned in the following claims are followed by reference marks or numbers, such reference marks or numbers have been affixed for the sole purpose of increasing the intelligibility of the claims and, consequently, they do not in any way constitute a limitation on the interpretation of each element identified, by way of example only, by such reference marks or numbers.

Claims

CLAIMS1. Control system (10) for controlling a valve or a pressure regulator, for combustible or explosive gas installations, comprising:- a valve body (51 ) connectable to two sections of a pipe, said valve body (51 ) comprising an internal passageway configured to connect said two sections of Pipe,- an intervention member (52) defined inside said valve body (51 ), said intervention member (52) being configured to act on a fluid within said valve body (51 ),- a threaded element (53) for controlling said intervention member (52), said threaded element (53) extending from said valve body (51 ), said threaded element (53) having an operating head (54), said threaded element (53) defining an operating axis (X1 ) with respect to which said threaded element is screwable or unscrewable with respect to a counter-threaded hole defined on said valve body (51 ) for controlling said intervention member (52),- a motor unit (11 ),- a rotatable slider (12) configured to couple with said operating head (54) to rotate said operating head (54) around said operating axis (X1 ),- rotation transmission means (40) from said motor unit (11 ) to said slider (12),- means configured to allow translation, during rotation, of said rotatable slider (12) along said operating axis (X1 ), in which said motor unit (11 ) comprises:- an electric motor (14) with a drive shaft (15),- a driving rotor (16), of magnet type, comprising an outer perimeter ring of first permanent magnets (17), said driving rotor (16) being attached tosaid drive shaft (15), a sealed box body (18) inside which an electrical insulation chamber (19) housing said electric motor (14), and a rotation chamber (20) inside which said driving rotor (16) rotates, are defined; said rotation transmission means (40) from said motor unit (11 ) to said slider (12) comprising a driven rotor (21 ) of magnet type, comprising in turn an inner perimeter ring of second permanent magnets (22), said driven rotor (21 ) being arranged coaxially with said driving rotor (16) and being arranged to surround with clearance said driving rotor (16).

2. Control system according to claim 1 , in which said first permanent magnets (17) of the driving rotor (16) are arranged angularly equidistant.

3. Control system according to one or more of the preceding claims, in which the first permanent magnets (17) of the driving rotor (16) are arranged with alternating polarity.

4. Control system according to one or more of the preceding claims, in which the second permanent magnets (22) of the driven rotor (21 ) are arranged angularly equidistant.

5. Control system according to one or more of the preceding claims, in which the second permanent magnets (22) are equidistant from each other at the same angle as the first permanent magnets (17).

6. Control system according to one or more of the preceding claims, wherein said rotation chamber (20) is defined by a continuous tumbler-shaped portion (23) of the sealed box body (18), said continuous tumbler-shaped portion (23) being at least partially interposed between the driving rotor (16) and the driven rotor (21 ), said continuous tumbler-shaped portion (23) being thuspositioned in the gap, i.e., in the space, between the driving rotor (16) and the driven rotor (21 ).

7. Control system according to one or more of the preceding claims, wherein said electrical insulation chamber (19) and said rotation chamber (20) are separated by an annular sealing wall (25), said annular sealing wall (25) being fixed within the sealed box body (18), said annular sealing wall (25) having a central bore (25a) traversed by the drive shaft (15).

8. Control system according to one or more of the preceding claims, wherein said sealed box body (18) is filled with synthetic resin (28) or other equivalent sealing material.

9. Control system according to one or more of the preceding claims, wherein an electronic board (30) for controlling and managing the electric motor (14) is also arranged within the sealed box body (18).

10. Control system according to one or more of the preceding claims, wherein said electronic board (30) is embedded in synthetic resin (28) or another equivalent sealing material.

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