Claims:WE CLAIM:
1. A control valve positioner (100) comprising:
• a housing (5) defining an inner wall and an outer wall;
• a component assembly (10) configured to be fastened to said inner wall of said housing (5), said component assembly (10) including:
o a magnet (30), a pilot valve (40), a nozzle (35) a calibration element (50) and a balancing unit (20) fastened to a monoblock plate (12); and
o means to fasten said monoblock plate (12) to said inner walls of said housing (5)
wherein said control valve positioner (100) is configured to the resist the angular displacement of said balancing unit (20).
2. The control valve positioner (100) as claimed in claim 1, wherein said balancing unit (20) includes:
• a coil (22) with a damping ring (32);
• a counterweight (24), said coil (22) and said counterweight (24) configured to be spaced apart;
• a flapper plate (26); configured for attachment of said coil (22) and said counterweight (24) on opposite sides;
• a pivot (28) located on said axis, said pivot (28) configured to connect said balancing unit (20) to said component assembly (12),
wherein said control valve positioner (100) is configured to the resist the angular displacement of said balancing unit (20) about said pivot (28) by a force induced in said damping ring (32) of due to induction of eddy currents in said damping ring (32).
3. The control valve positioner (100) as claimed in claim 1, wherein a resilient element (29) is provided between said flapper plate (26) and said counterweight (24).
4. The control valve positioner (100) as claimed in claim 1, wherein semicircular grooves (25) are provided on said counterweight (24) to provide access for fastener installation.
5. The control valve positioner (100) as claimed in claim 1, wherein an air filter regulator (60) is attached to said control valve positioner (100).
6. The control valve positioner (100) as claimed in claim 4, wherein an auxiliary air inlet port (62) and an air inlet pressure gauge (64) are provided on said air filter regulator (60).
7. The control valve positioner (100) as claimed in claim 1, wherein said coil (22) includes a coil winding (31), an insulating former (33) and said damping ring (32), said damping ring (32) configured to be induced with eddy currents.
, Description:FIELD
The present disclosure relates to a control valve positioner.
DEFINITION
Control valve positioner - a control valve positioner is defined as a device used to increase or decrease the pressure of a fluid driving an actuator of a control valve, until the valve reaches a position balanced to a process parameter signal.
Monobloc plate – a plate typically having complex profiles made by casting into a single piece
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Mechanical types of control valve positioners are currently used to actuate valves by a desired amount which is proportional to an inlet signal such as air pressure. The inlet signal is fed to a mechanism and a corresponding output signal is generated based on desired displacement of an element such as an actuator. The actuator link is further connected to a valve stem which controls or positions the valve to the desired position. However, the positioning device is subjected to vibrations as it is mounted on other equipment or forms a part of a machine. This causes loss of proportional control of the actuator, leading to deviation from a desired displacement value of the valve. As a result the valve either displaces greater than or lesser than the desired amount. Further, if the components of the positioning device are not balanced properly, vibrations could damage the control valve positioner leading to decrease in the useful life of the positioning device. In addition to this, there are many other sub-assemblies of components interacting with each other in a control valve positioner such as a magnet, and a calibration element. This makes the maintenance and servicing of the positioning device difficult, thus requiring a labor intensive dismantling procedure.
There is, therefore, felt a need for a control valve positioner that solves the aforementioned problems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a control valve positioner that offers increased stability against vibrations.
Another object of the present disclosure is to provide a control valve positioner that offers ease of assembly and dismantling.
Yet another object of the present disclosure is to provide a control valve positioner that offers enhanced damping against torsional vibrations.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a control valve positioner comprising a component assembly mounted on the interior of the device; a balancing unit configured on the component assembly, the balancing unit includes a coil and a counterweight attached to opposite ends of a flapper plate. The balancing unit is configured to rotate around a pivot, the pivot defined at the center of gravity of the coil and the counterweight assembly. A magnet, a pilot valve, a calibration element lie configured on the component assembly.
In a preferred embodiment, the control valve positioner further comprises a resilient element attached between the plate and the counterweight which provides resistance against external vibrations.
In a preferred embodiment, semicircular grooves are provided on the counterweight to provide access for fastener installation.
In a preferred embodiment, an air filter regulator is configured to be attached to the control valve positioner.
An auxiliary air inlet port and an air inlet pressure gauge are provided on the air filter regulator.
In a preferred embodiment, the balancing assembly, the magnet, the pilot valve and the calibration element are fastened to the monobloc plate assembly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A control valve positioner, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 shows an isometric view of a control valve positioner, in accordance with an embodiment of the present disclosure.
Figure 2 shows an exploded view of the control valve positioner of the Figure 1.
Figure 3 shows a top view of the balancing assembly of the Figure 1.
Figure 4 shows a front view of the balancing assembly of the Figure 1.
Figure 5 shows a side view of the balancing assembly of the Figure 1.
Figure 6 shows a front view of the coil of the Figure 4.
Figure 7 shows a sectional view of the coil.
Figure 8 shows an isometric view of the coil of the Figure 6.
Figure 9 shows an exploded view of the coil of the Figure 6.
Figure 10 shows an exploded view of the control valve positioner.
LIST OF REFERENCE NUMERALS
5 – housing
6 – primary air inlet port
7 – air outlet
10 – component assembly
12 – monobloc plate
20 – balancing unit
22 - coil
24 – counterweight
25 – semicircular grooves
26 – flapper plate
23 – iron cup
27 – air gap
28 – pivot
29 – resilient element
30 – magnet
31 – coil winding
32 – damping ring
33 – insulating formar
35 – nozzle
40 – pilot valve
50 – calibration element
60 – air filter regulator
62 – auxiliary air inlet port
64 – air inlet pressure gauge
66 – air outlet pressure gauge
100 – control valve positioner
DETAILED DESCRIPTION
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Description of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practised and to further enable those of skill in the art to practise the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiment herein.
The description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Referring to Figures 1-5, a control valve positioner 100 (hereinafter referred to as device 100) will be now described, in accordance with an embodiment of the present disclosure. The control valve positioner 100 comprises a housing (5) defining an interior side and an exterior side. The control valve positioner 100 further comprises a component assembly 10 that is mounted on an inner wall on the interior side of the housing 5. The component assembly 10 facilitates mounting of a balancing unit 20, a magnet 30, pilot valve 40, a calibration element 50 and a nozzle 35. In an embodiment, the balancing unit 20, the magnet 30, the pilot valve 40, the calibration element 50 and the nozzle 35 are fastened to the component assembly 10 with the help of a monobloc plate 12. This makes the construction of the control valve positioner 100 less complex and offers ease of maintenance and servicing.
The balancing unit 20 includes a coil 22, a counterweight 24, a flapper plate 26 and a resilient element 29. In an embodiment, as shown in figures 3-5 the resilient element 29 is in the form of an L-shaped spring disposed between the flapper plate 26 and the counterweight 24. The arrangement of resilient element 29, the flapper plate 26 and the counterweight 24 provides resistance against external vibrations subjected to the control valve positioner 100. The coil 22, the counterweight 24 and the spring 29 are attached to the flapper plate 26. The coil 22 and the counterweight 24 are attached on opposite ends of the flapper plate 26. Thus, the coil 22 lies attached to the bottom end of the balancing unit 20, while the counterweight 24 lies on the top end of the balancing unit 20. The balancing unit 20 is configured to be rotated around a pivot 28. The location of the pivot 28 is such that the centre of gravity of the balancing unit 20 coincides with the location of the pivot 28. This facilitates balancing of the coil 20 and the counterweight 24 assembly, as mass of the coil 22 is supported opposite to mass of the counterweight 24 along the monobloc plate 26. The balancing assembly 20 rotates about the pivot 28 when subjected to vibrations. The balancing of the balancing assembly 20 is desired, as the control valve positioner 100 is subjected to vibrations transferred from the coil 20 and the counterweight 24 assembly further attached to other equipment or machinery. Thus, the wear and tear of the control valve positioner 100 is reduced, as unbalanced forces acting upon the balancing unit 20 are reduced.
The coil 22 comprises a winding 31 on an insulating former 33 along with an electrically conductive damping ring 32. The damping ring 32 provides eddy current damping in conjunction with the magnet 30. The coil 22 includes an iron cup 23 attached to the monobloc plate 12 for accommodating the magnet 30 which is separated by an air gap 27. The L shape resilient element 29, the counter weight 24, the plate 26, the pivot 28 and coil 22 form a spring-mass system. This system has an angular (rotational) degree of freedom around the pivot 28 and consequently a mechanical angular vibration resonance mode. The damping ring 32 in the coil 22 facilitates mechanical damping of this vibration mode due to eddy currents induced in the damping ring 32.
The control valve positioner 100 is provided with semicircular grooves 25 on the counterweight 24 to provide access for fastener installation, as the balancing assembly 20 is installed inside a housing 5 of the control valve positioner 100. The component assembly 10 is mounted on the housing 5, which typically is a bolted joint construction. This facilitates ease of assembly as well as disassembly, as only few bolts have to be loosened without disassembling the entire valve positioner 100.
The control valve positioner 100 has a primary air inlet port 6 and an air outlet port 7 for exchange of pressurized fluid such as air. The positioner 100 has an air inlet port 6 and an air outlet port 7. The primary air inlet port 6 facilitates attachment of an air filter regulator 60. In the absence of the primary air inlet port 6, the air filter regulator 60 would have been required to be mounted on the valve. The air filter regulator 60 on one end is connected to the control valve positioner 100. The air filter regulator 60 is further provided with an auxiliary air inlet port 62. The auxiliary air inlet port 62 and the primary air inlet port 6 facilitate selective incoming of the pressurized air supply to the control valve positioner 100. Thus, when air filter regulator 60 is in use, the primary air inlet port 6 is disabled and the auxiliary air inlet port 62 is functional. When the air filter regulator 60 is not in use, the primary air inlet port 6 is functional. An air inlet pressure gauge 64 is provided on the other end of the air filter regulator 60 to facilitate air inlet pressure measuring. Similarly, an air outlet pressure gauge 66 is provided in the proximity of the air outlet 7. The air outlet 7 is further connected to an actuator (not shown in any figures), which provides air supply for positioning of a valve connected thereto.
In an alternate embodiment, the air filter regulator 60 is integral to the valve positioner device 100.
The balancing unit 20, a magnet 30, a pilot valve 40 and a calibration element 50 are fastened to the monobloc plate 12. In an embodiment, the fasteners are of screws of varying sizes to easily replace or service the positioning device 100.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a control valve positioner, which:
• offers efficient proportional control over actuation of a valve;
• is simple in construction; and
• is easy for maintenance and servicing.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.