U.S. patent number 10,876,645 [Application Number 16/354,802] was granted by the patent office on 2020-12-29 for gas line control system and modular variable pressure controller.
This patent grant is currently assigned to VRG CONTROLS, LLC. The grantee listed for this patent is VRG CONTROLS, LLC. Invention is credited to James Michael Garvey, Vladimir Rimboym.
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United States Patent |
10,876,645 |
Garvey , et al. |
December 29, 2020 |
Gas line control system and modular variable pressure
controller
Abstract
A pneumatically controlled assembly, system, method and device
for the regulation of pressure of a gas as it flows in a
pressurized line and including at least one loading valve which is
set to respond to variations in pressure in conjunction with a
pneumatically actuated process control valve so as to effectively
regulate and maintain pressure of the gas in the pressurized
line.
Inventors: |
Garvey; James Michael (Wheaton,
IL), Rimboym; Vladimir (Highland Park, IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
VRG CONTROLS, LLC |
Highland Park |
IL |
US |
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Assignee: |
VRG CONTROLS, LLC (Highland
Park, IL)
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Family
ID: |
1000005268811 |
Appl.
No.: |
16/354,802 |
Filed: |
March 15, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190211940 A1 |
Jul 11, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15218186 |
Jul 25, 2016 |
10234047 |
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13899013 |
May 21, 2013 |
9400060 |
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61649460 |
May 21, 2012 |
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61825408 |
May 20, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K
17/105 (20130101); G05D 16/166 (20130101); Y10T
137/777 (20150401); Y10T 137/0318 (20150401); Y10T
137/86919 (20150401) |
Current International
Class: |
F16K
31/12 (20060101); G05D 16/16 (20060101); F16K
17/10 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Arundale; Robert K
Attorney, Agent or Firm: Bishop, Diehl & Lee. Ltd.
Parent Case Text
RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No.
15/218,186 filed Jul. 25, 2016, titled "GAS LINE CONTROL SYSTEM AND
MODULAR VARIABLE PRESSURE CONTROLLER" now U.S. Pat. No. 10,234,047,
which is a divisional of U.S. application Ser. No. 13/899,013,
filed May 21, 2013, titled "GAS LINE CONTROL SYSTEM AND MODULAR
VARIABLE PRESSURE CONTROLLER" now U.S. Pat. No. 9,400,060, which
claims priority to U.S. Provisional Application No. 61/649,460
titled "Gas Line Control System" and filed on May 21, 2012 as well
as U.S. Provisional Application No. 61/825,408 titled "Gas Line
Control System," filed on May 20, 2013. The '047 and '060 patents,
as well as the '460 and '408 provisional applications are all
incorporated herein by reference.
Further, U.S. Pat. No. 5,762,102 to Rimboym, titled "Pneumatically
Controlled No-Bleed Valve And Variable Pressure Regulator" issued
to Becker Precision Equipment, Inc. on Jun. 9, 1998, is also
incorporated herein by reference.
Claims
What is claimed is:
1. A method for controlling a fluid supply through a delivery line
having a process control valve therein to maintain a supply side
pressure and a delivery side pressure, and a pneumatic actuator
having a first pressure chamber and a second pressure chamber and
used to operate the process control valve, the method comprising
the steps of: setting a delivery side target pressure range for the
fluid supply; sensing the delivery side pressure; operating the
pneumatic actuator in one of the following ways: maintaining the
actuator in a static state when the delivery side pressure is
within the target range; moving the actuator to open the process
control valve when the delivery side pressure is below the target
range; moving the actuator to close the process control valve when
the delivery side pressure is above the target range; and applying
0.001'' hardcoat anodizing to create a barrier between aluminum and
stainless steel screws to eliminate electrolysis and aluminum
corrosion; wherein, the first and second pressure chambers of the
actuator are responsive to a first loading valve fluidly coupled to
the first pressure chamber and a second loading valve fluidly
coupled to the second pressure chamber, and the first loading valve
and the second loading valve open and close in response to the
delivery side pressure to change a position of the actuator and
thereby operate the process control valve.
2. The method for controlling a fluid supply through a delivery
line as set forth in claim 1, further comprising moving the first
loading valve and the second loading valve synchronously between
the closed position and the open position.
3. The method for controlling a fluid supply through a delivery
line as set forth in claim 1, further comprising opening the first
loading valve to change the position of the actuator and move the
process control valve toward a fully closed position.
4. The method for controlling a fluid supply through a delivery
line as set forth in claim 2, further comprising opening the first
loading valve to change the position of the actuator and move the
process control valve toward a fully closed position.
5. The method for controlling a fluid supply through a delivery
line as set forth in claim 1, further comprising opening the second
loading valve to change the position of the actuator and move the
process control valve toward a fully open position.
6. The method for controlling a fluid supply through a delivery
line as set forth in claim 2, further comprising opening the second
loading valve to change the position of the actuator and move the
process control valve toward a fully open position.
Description
TECHNICAL FIELD OF THE INVENTION
The present device relates to devices and systems for regulation
and control of pressure in pressurized gas delivery lines.
Particularly, the present device and system relate to a variable
pressure controller (VPC) for regulation and control of fluid flow
in a delivery line.
BACKGROUND OF THE INVENTION
Pressure regulators equipped with variable pressure regulator pilot
valves are used as operating regulators, monitors, stand-by
regulators and relief valves. Prior to the invention of U.S. Pat.
No. 5,762,102, such valves were designed to maintain the desired
pressure of fluid in a delivery line by operating with a constant
"bleed" from the valve. This was not only wasteful but, in the case
of some fluids, was environmentally undesirable. Environmental
costs and problems are caused by discharge of pollutants to the
air. Bleed gas from natural gas pipelines to the atmosphere year
after year only adds to the growing environmental problem. Overall,
industry estimates place the discharge of natural gas to the
atmosphere from a single controller operating with constant bleed
to the atmosphere, in excess of 300,000 standard cubic feet (SCF)
per year.
In the present invention, while the no-bleed controller is of
import, embodiments of the present invention address problems with
the following key features: VPC with one common block and external
manifolds; VPC with two different internal loading valves; VPC with
Manual Operation Valve (Rotary Type)--attached via manifold
configuration; VPC with external insertion of Nozzle Assembly;
VPC-PID with variable gain; System configurations above adaptable
to diaphragm style rotary pneumatic positioner via addition of
proportional feedback mechanism; Double-acting, single-acting
(reverse) and single-acting (direct) in one common VPC
configuration; VPC with conditioning of output and exhaust flow
paths via manifolds; Interchangeability of "normally open" and
"normally closed" internal loading valves in same body; and
Coupling of the "derivative" adjustable orifice on output of "ID"
models--derivative adjustment is configured in manifold system and
also incorporates "flow conditioning."
These and other problems are solved by the present VPC device and
system.
SUMMARY OF THE INVENTION
The following presents a simplified summary of embodiments of the
system and method of the disclosed invention. The summary is
intended to introduce particular useful elements, which may be
critical to a particular embodiment and optional for other
embodiments. Though not specifically summarized here, other
critical and optional elements, including combinations of such
elements, may also be possible.
Generally speaking, a pneumatic valve pressure controller system
having a fluid supply line and a variable pressure controller
coupled to a process control valve within the supply line, is
described.
In a particular embodiment, a supply regulator is fluidly coupled
to the fluid supply line upstream of the process control valve and
an actuator is operably connected to the process control valve, the
actuator having a first pressure chamber and a second pressure
chamber. A sensing diaphragm connected to the fluid supply line
determines a relative pressure in the fluid supply line on the
outlet end side of the process control valve, while a first loading
valve is fluidly coupled to the first pressure chamber and
responsive to the sensing diaphragm and a second loading valve is
fluidly coupled to the second pressure chamber and responsive to
the sensing diaphragm. In such an embodiment, the first loading
valve and the second loading valve open and close in response to
the sensing diaphragm to change a position of the actuator and
thereby operate the process control valve.
In an embodiment of the method for controlling a fluid supply
through a delivery line having a process control valve therein to
maintain a supply side pressure and a delivery side pressure, and a
pneumatic actuator having a first pressure chamber and a second
pressure chamber and used to operate the process control valve, the
steps include setting a delivery side target pressure range for the
fluid supply, sensing the delivery side pressure, and operating the
pneumatic actuator to either maintain the actuator in a static
state when the delivery side pressure is within the target range or
move the actuator to adjust the process control valve position when
the delivery side pressure is outside the target range.
In a specific embodiment of the method, the first and second
pressure chambers of the actuator are responsive to a first loading
valve fluidly coupled to the first pressure chamber and a second
loading valve fluidly coupled to the second pressure chamber, and
the first loading valve and the second loading valve open and close
in response to the delivery side pressure to change a position of
the actuator and thereby modulate the position of the process
control valve.
Further, a variable pressure controller is also described and
claimed. Generally speaking, the controller is comprised of a first
fluid interface for coupling to a fluid line upstream of a process
control valve, a sensing mechanism positioned at the first fluid
interface and responsive to a pressure in the fluid line upstream
of a process control valve, a first loading valve responsive to the
sensing mechanism, a second loading valve responsive to the sensing
mechanism, a first manifold comprised of two outlet ports, wherein
one outlet port is coupled to a first channel fluidly coupled to
the first loading valve and one outlet port is coupled to a second
channel fluidly coupled to the second loading valve, and a second
manifold comprised of two outlet ports, wherein one outlet port is
coupled to a first channel fluidly coupled to the first loading
valve and one outlet port coupled to a second channel fluidly
coupled to the second loading valve.
In a specific embodiment of the VPC, at least one module capable of
interfacing with at least one of the first manifold and the second
manifold. Additionally, the first loading valve and the second
loading valve may be one of either a "normally closed" or "normally
open" valve configuration. The pair of loading valves may be
similar or dissimilar to one another.
The described features may be combined as appropriate, as would be
apparent to one of skill in the art reading this disclosure. Many
of these features and combinations will be more readily apparent
with reference to the following detailed description and the
appended drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the subject
matter sought to be protected, there are illustrated in the
accompanying drawings embodiments thereof, from an inspection of
which, when considered in connection with the following
description, the subject matter sought to be protected, its
construction and operation, and many of its advantages should be
readily understood and appreciated.
FIG. 1 is a schematic of an embodiment of the VPC power module and
manifolds illustrating the plug-and-play versatility of the
system;
FIG. 2 is a schematic of an embodiment of a double-acting system
with two normally-closed loading valves illustrating a condition
where the downstream pressure set-point is satisfied and the system
is in a steady state with the process control valve at a first
position;
FIG. 3 is a schematic of the embodiment of FIG. 2 illustrating a
condition where the downstream pressure rises above a set-point and
the process control valve reacts to close further;
FIG. 4 is a schematic of the embodiment of FIG. 2 illustrating a
condition where the downstream pressure returns to a set-point and
the system is again in a steady state with the process control
valve at a second position;
FIG. 5 is a schematic of the embodiment of FIG. 2 illustrating a
condition where the downstream pressure falls below a set-point and
the process control valve reacts to open further;
FIG. 6 is a schematic of the embodiment of FIG. 2 illustrating a
condition where the downstream pressure returns to a target
pressure (i.e., set-point) and the system is once again in a steady
state with the process control valve at a third position;
FIGS. 7A-E are a sequence of schematics, similar to FIGS. 2-6, of
an embodiment of a double-acting system with two normally open
loading valves illustrating steady state and upset conditions of
the system;
FIGS. 8A-E are a sequence of schematics, similar to FIGS. 2-6, of
an embodiment of a single-acting system with two normally-closed
loading valves illustrating steady state and upset conditions of
the system;
FIGS. 9A-E are a sequence of schematics, similar to FIGS. 2-6, of
another embodiment of a single-acting system with the addition of a
"derivative" function adjustment and with two normally-closed
loading valves illustrating steady state and upset conditions of
the system;
FIG. 10 is a cross-sectional view of one valve section of an
embodiment of the VPC power module showing the interchangeability
of a normally-closed loading valve and a normally-open loading
valve;
FIG. 11 is a schematic illustrating a single-acting VPC with a
normally-closed loading valve configuration and a proportional
valve position feedback acting as a pneumatic valve positioner;
FIG. 12 is a schematic showing a system having a VPC having
dissimilar normally-closed loading valve and a normally-open
loading valve with independent sensitivity adjustments for each
loading valve;
FIGS. 13-13d are various views of an optional valve manual override
(VMO), including illustrating the VMO in automatic mode, neutral
mode, open mode, and closed mode, and demonstrating manifold
configuration between VMO body and pneumatic connection ports;
FIGS. 14 and 15 illustrate an embodiment of the VPC power module
and the interchangeable manifolds; and
FIGS. 16A/B through 29A/B are schematics of the numerous system
variations (FIGS. 16A-29A) and the corresponding VPC model (FIGS.
16B-29B).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
While this invention is susceptible of embodiments in many
different forms, there is shown in the drawings and will herein be
described in detail a preferred embodiment of the invention with
the understanding that the present disclosure is to be considered
as an exemplification of the principles of the invention and is not
intended to limit the broad aspect of the invention to embodiments
illustrated.
Referring to FIGS. 1-29, there are illustrated embodiments of a
fluid line control system, the system being generally referenced in
the drawing figures by the numeral 10. The control system 10 is
comprised of a fluid line 12 having a process control valve 14
coupled therein and a variable pressure controller (VPC) 20
indirectly coupled to the process control valve 14. The process
control valve 14 has a supply side pressure (P1) and a delivery
side pressure (P2), the latter of which is controlled through
operation of the process control valve 14. The VPC 20 is comprised
of a power module 22 and interchangeable manifolds 30 to achieve
different configurations/models, as further explained below.
Process Control Valve
In the embodiment of FIGS. 2-6, the process control valve 14 is
directly operated by a pneumatic actuator 32 having a first (or
upper) pressure chamber 34 and a second (or lower) pressure chamber
36. The pressure chambers, 34 and 36, are fluidly coupled to first
and second loading valves, 40 and 42, respectively, through
adjustable orifices, 44A and 44B. In the double-acting models of
the system 10, the process control valve is operated pneumatically,
requiring the fluid pressures in the first and second chambers, 34
and 36, to move the actuator in either direction. Comparatively, in
the single-acting embodiments, the process control valve 14
includes a spring-piston actuator 32 (e.g., FIG. 18A), where the
fluid pressure of the system 10 is used to drive the actuator in a
single direction against the force of the spring 41. Alternatively,
the actuator of the process control valve 14 may be operated by a
spring/diaphragm 50 (e.g., FIG. 21A). Either of the embodiments
described for actuator 32 of the process control valve 14 for the
single-acting models may be reversed for particular applications
(e.g., FIGS. 19 and 26).
Loading Valves
The loading valves of the VPC power module 22 are preferably
loading valves, 40, 42, which are preferably normally closed
valves. These valves operate in response to movement of an internal
mechanism 16, which is in turn responsive to a control spring 24
and sensing diaphragm 26 coupled to a sensing pressure at the
delivery side of the process control valve 14. A set-point of the
delivery side pressure (P2) is set via set-point adjustment screw
28. Alternatively, as shown in FIG. 10, the valves may utilize
loading valves 45 (FIG. 10), which are of a normally-open
configuration. As two loading valves are used, the pair of loading
valves may be similar (i.e., both normally closed loading valves or
both normally open loading valves) or the valves may be dissimilar
(i.e., one normally closed loading valve and one normally open
loading valve).
Operation of Double-Acting VPC System
Generally speaking, operations of the system 10 using different
models of the VPC 20 are similar. In a double-acting model, when
the sensing pressure is equal to the VPC set-point, the net force
on the VPC power module 22 is zero. This is the equilibrium or
"balanced" condition where the sensing pressure that pushes down on
a sensing diaphragm 26 and the force of the control spring 24 that
pulls up on the sensing diaphragm 26 are equal. When the VPC 20
achieves equilibrium (e.g., FIG. 2), the top loading valve 40 and
bottom loading valve 42 will remain closed maintaining a constant
output pressure to the top and bottom chambers, 34 and 36,
respectively, of the process control valve actuator 32. The VPC
will exhibit zero emissions at this state.
From the balanced position two possible scenarios can occur: the
sensing pressure can rise above the set point, or the sensing
pressure can fall below the set-point. If the sensing pressure
rises above the VPC set-point (e.g., FIG. 3), the net force on the
VPC power module 22 is downward. The top loading valve 40 will open
and divert pressure from the top chamber 34 of the double acting
actuator 32 to exhaust. The bottom loading valve 42 will remain
closed and full supply pressure shall continue to be applied to the
bottom chamber 36 of the double acting actuator 32. The combination
of these actions creates a differential pressure to be applied to
the double acting actuator 32 that will move the process control
valve 14 toward the closed position.
FIG. 4 illustrates the resulting corrective action of the closed
process control valve.
Conversely, if the sensing pressure falls below the VPC set-point
(e.g., FIG. 5), the net force on the VPC power module 22 is upward.
The bottom loading valve 42 will open and divert pressure from the
bottom chamber 36 of the double acting actuator 32 to exhaust. The
top loading valve 40 will remain closed and full supply pressure
shall continue to be applied to the top chamber 34 of the double
acting actuator 32. The combination of these actions creates a
differential pressure to be applied to the double acting actuator
32 that will move the process control valve toward the open
position.
FIG. 6 illustrates the resulting corrective action of the open
process control valve.
Remaining with double-acting VPC model of FIGS. 2-6, a step-wise
operation of an embodiment of the system 10 is provided below.
With reference to FIG. 2, the following is illustrated: a. The
energy to operate the actuated process control valve 14 is obtained
from the differential between supply gas pressure and exhaust
pressure. b. When the downstream pressure (P2) is equal to a
set-point a force equilibrium will exist between the VPC sensing
diaphragm 26 and the control spring 24. c. The force equilibrium
results in the VPC internal mechanism 16 being centered. d. With
the VPC mechanism 16 centered, the first loading valve 40 and the
second loading valve 42 remain closed and full supply pressure
passes through the adjustable orifices, 44A and 44B, and load both
pressure chambers 34 and 36 of the pneumatic actuator 32 equally.
e. At the steady state centered position, the VPC 20 achieves ZERO
steady exhaust.
With reference to FIG. 3, the following is illustrated: a. When the
downstream pressure (P2) is rises above set-point the VPC sensing
diaphragm 26 force will exceed the control spring 24 force. b. The
downward force imbalance results in the VPC internal mechanism 16
shifting downward. c. With the VPC internal mechanism 16 shifting
downward, the first loading valve 40 will open slightly and second
loading valve 42 will remain closed. d. When the first loading
valve 40 opens it causes the pressure loading the first pressure
chamber 34 of the pneumatic actuator 32 to be directed to the
exhaust 46. e. The second loading valve 42 remains closed causing
full supply gas pressure to pass through the adjustable orifice 44
loading the second pressure chamber 36 of the valve actuator 32. f.
With the pressure differential across the valve actuator 32, the
process control valve 14 moves toward the CLOSED position.
With reference to FIG. 4, the following is illustrated: a. When the
process control valve 14 moves toward the CLOSED position, the
downstream pressure will drop and return to a value equal to the
set-point. b. When the downstream pressure (P2) is equal to
set-point, a force equilibrium will exist between the VPC sensing
diaphragm 26 and the control spring 24. c. The force equilibrium
results in the VPC internal mechanism 16 being centered. d. With
the VPC internal mechanism 16 centered, the first loading valve 40
and the second loading valve 42 remain closed and full supply
pressure passes through the adjustable orifices 44A and 44B and
loads both pressure chambers, 34 and 36, of the pneumatic actuator
32 equally. e. At the steady state centered position, the VPC 20
achieves ZERO steady exhaust.
With reference to FIG. 5, the following is illustrated: a. When the
downstream pressure (P2) is falls below the set-point the VPC
control spring 24 force will exceed the sensing diaphragm 26 force.
b. The upward force imbalance results in the VPC internal mechanism
16 shifting upward (as indicated by the arrow). c. With the VPC
internal mechanism 16 shifting upward, the second loading valve 42
will open slightly and first loading valve 40 will remain closed.
d. When the second loading valve 42 opens, it causes the pressure
loading the second pressure chamber 36 of the pneumatic actuator 32
to be directed to the exhaust 46. e. The first loading valve 40
remains closed, causing full supply gas pressure to pass through
the adjustable orifice 44 loading the first pressure chamber 34 of
the valve actuator 32. f. With the pressure differential across the
valve actuator 32, the process control valve 14 moves toward the
OPEN position. g. When the process control valve 14 moves toward
OPEN position, the downstream pressure will rise and return to a
value equal to the set-point.
With reference to FIG. 6, the following is illustrated: a. When the
downstream pressure (P2) is equal to a set-point, a force
equilibrium will exist between the VPC sensing diaphragm 26 and the
control spring 24. b. The force equilibrium results in the VPC
internal mechanism 16 being centered. c. With the VPC internal
mechanism 16 centered, the first and second loading valves, 40 and
42, remain closed and full supply pressure passes through the
adjustable orifices, 44A and 44B, and loads both pressure chambers,
34 and 36, of the pneumatic actuator 32 equally. d. At the steady
state centered position, the VPC 20 achieves ZERO steady
exhaust.
While FIGS. 2-6 illustrate and the above describes a double-acting
actuator operated process control valve using normally-closed
loading valves, it should be understood that systems using the
normally-open loading valves operate similarly. For example, the
steady state and upset state conditions are illustrated in FIGS.
7A-E featuring a VPC with normally-open valves.
Operation of Single-Acting VPC System
Similarly, referring to FIGS. 8A-E and 9A-E, a single-acting
version can be used and works similarly. A notable difference is
that the first loading valve 40 and the second loading valve 42
would be connected in common and would work synchronously. These
valves, 40 and 42, would still be normally closed and would
translate to "cylinder load" and "cylinder unload."
That is, for single-acting systems where a single pressure output
is involved, there shall be one valve designated as the "load"
valve and one valve designated as the "unload" valve. Each valve
shall be normally closed for this type of system. The "load" and
"unload" valves are connected to a common pressurized system. In
this configuration, the VPC 20 has three different states: (1)
steady state; (2) unloading state; and (3) loading state.
In the steady state, both the "load" and "unload" valves are
closed, resulting in no pressurizing or depressurizing of the
pneumatic actuator system. The process control valve 14 is said to
be in a steady state or static.
When an upset in the process variable occurs, the VPC 20 may enter
the unload state or loading state. In the unload state, the force
unbalance between the VPC sensing diaphragm 26 and the control
spring 24 causes a shift of the VPC 20 to open the "unload" valve
and maintain the "load" valve in a closed position. This causes the
system 10 to vent or exhaust pressure from the pneumatic actuator
32 resulting in a new position of the process control valve 14.
Conversely, when an upset occurs to place the VPC 20 in the
"loading" state, the unbalance between the sensing diaphragm 26 and
the control spring 24 causes a shift of the VPC 20 to open the
"load" valve and keep the "unload" valve closed. This causes the
system 10 to increase pressure to the pneumatic actuator 32
resulting in a new position of the process control valve.
Ultimately, in both cases, the new position of the process control
valve 14 will result in attainment of equilibrium and return to the
steady state, as described above.
Additionally, in the single-acting (SA) model of the VPC, when the
sensing pressure is equal to the VPC set-point, the net force on
the VPC power module 22 is zero. As noted, this is an equilibrium
condition where the sensing pressure that pushes down on the
sensing diaphragm 26 and the force of the control spring 24 that
pulls up on the sensing diaphragm 26 are equal. When the VPC 20
achieves this equilibrium, the supply loading valve 40 and exhaust
loading valve 42 will remain closed maintaining a constant output
pressure to the process control valve 14. The VPC 20 will exhibit
zero emissions at this state.
During operation, the equilibrium or steady state (static) is
preferred, so the system operates to return to this state whenever
an upset occurs. As noted, two possible scenarios can occur from
the balance state: the sensing pressure can rise above the set
point or fall below the set point. If the sensing pressure rises
above the VPC set-point, the net force on the VPC power module is
downward. The exhaust loading valve will close or stay closed. The
supply loading valve opens, increasing the flow of supply gas to
the output port. The combination of these actions creates a rise in
output pressure. If the sensing pressure falls below the VPC
set-point the net force on the VPC power module is upward. Now the
supply loading valve will close or stay closed and the exhaust
loading valve opens, increasing the flow of gas to the exhaust
port. The combination of these actions decreases the output
pressure. In order to control how much gas passes through the
loading valve, adjustable orifices are installed to restrict the
flow via the supply and the exhaust.
Modularity of VPC
A key aspect of the system 10 is the modularity of the VPC 20. A
modular format of the VPC 20 is illustrated in FIG. 1. The modular
format of power modules 30 and the internal loading valve logic
(FIG. 10) provide the ability to configure the device for
double-acting (DA) output or single-acting (SA) output within the
same system. Existing technology does not offer a modular format
that allows reconfiguration between the double-acting output and
single-acting output configurations.
Accordingly, the VPC 20 is capable of being configured in a number
of different models as a result of the adaptability of the single
platform power module 22 and the various "plug-and-play" modules.
Exemplary embodiments of these "plug-and-play" modules (labeled
1-4) to form discrete VPC models (labeled 1-5, with corresponding
labeled modules forming the particular VPC model) are set forth in
FIG. 1. Each model 1-5 corresponds to a set of operating parameters
referenced in TABLE 1 below. More detailed illustrations and
descriptions of such modules and VPC models, as well as possible
alternatives and accessory devices, follow.
TABLE-US-00001 TABLE 1 Controller Model VPC-SA- VPC-SA- VPC-SA-
VPC-DA- VPC-DA- BV BV-ID BV-GAP BV SN Type Variable Variable
Discrete Variable Variable (On-Off) Outputs Single Acting (1)
Double Acting (2) Internal Normally-Closed Loading Valve Normally
Valve Open Logic Loading Valve Setpoint 1.25-1500 psig (9.0-10,342
kPa) Range Temperature -20.degree. F. to +160.degree. F.
(-29.degree. C. to +71.degree. C.) Range
The various VPC models are so configured to be applicable to
different fluid systems. In operation, the embodiments operate in a
similar manner, with variations such as flow direction, valving,
etc., dictated by the accompanying modules and accessory devices.
And the simple modularity allows conversion between models. For
example, the VPC has the ability to convert between a normally open
loading valve style (SN) to normally closed loading valves (BV).
Further, the manifolding provided by the power module 22 provides
the ability to convert to and from single acting to double acting
models. Additionally, when configured as a single acting model, the
VPC can convert between "direct acting" and "reverse acting"
control logic.
Referring to FIGS. 16-29 (A and B), the modularity of the VPC 20
can be most readily appreciated. In these figures the numerous VPC
models are shown schematically placed within a fluid control system
10 (i.e., FIGS. 16A-29A) and labeled for adjusting the set-point
screw 28 and sensitivity (i.e., FIGS. 16B-29B).
VPC Modules
Referring to FIGS. 1, 14 and 15, several different manifolds 30 are
illustrated. These manifolds 30 connectable to the VPC power module
22 and create the various VPC models described. As illustrated, the
individual manifolds 30 may include various configurations,
channels and adjustable orifices to accommodate single-acting and
double-acting configurations, as well as normally-closed loading
valve and normally-open loading valve configurations. The manifolds
30 connect and bolt (or otherwise lock) onto the power module
22.
System Accessories
Referring now to FIGS. 11-13, numerous system 10 accessories can be
viewed. These accessories also add to the modularity of the VPC 20.
As noted above, the VPC 20 may be configured with either normally
open loading valves (seat & nozzle valves 45) or normally
closed (loading valves 40) internal logic using the same VPC base
platform 22. Interchangeable internal valve format "Logic Exchange"
(see FIG. 10) allows the system 10 to be configured for multiple
control applications.
As shown in FIG. 1, the "connecting" manifolds 23 of the VPC power
module 22 provide unique flow conditioning that optimizes flow
characteristics of internal logic (loading valves 40 and 42),
allowing greater control capabilities of the VPC 20. This is
particularly important when coupled with additional control devices
such as a volume booster 33 (see FIG. 12) and a pneumatic
positioner 35 (see FIG. 11). Existing technology does not integrate
any "flow conditioning" via manifolding, which lessens control
capabilities.
The VPC derivative adjustment (orifice) is pneumatically coupled
with the VPC output pressure via installation in same manifold
which provides improved control capabilities. The derivative
adjustment is an adjustable orifice (restriction) that is installed
in parallel with the output to the control element (actuator 32 or
pneumatic positioner 35) with a volume tank 37 installed downstream
of the derivative adjustment. The resulting configuration provides
for a delayed response of the VPC output signal to the control
element (actuator 32 or valve positioner 35). The derivative
adjustment affects the rate of response of the output to the
control element (actuator 32 or valve positioner 35). Existing
systems utilize a derivative adjustment (orifice) that is installed
as a separate component (adjustable orifice) from the output
function which does not provide the same optimized characteristics
as achieved in the VPC 20 of the present system 10.
The base VPC 20 of system 10 offers numerous additional advantages
over existing technology. As shown in FIG. 12, the VPC 20 allows
incorporation of two (2) dissimilar internal valves (i.e.,
normally-closed loading valve and normally-open loading valve) to
achieve a completely new control configuration for application
optimization. Current technology must utilize two (2) identical
internal loading valves due to limitations of design. Also shown,
the VPC 20 also allows incorporation of two (2) independent
sensitivity adjustments for each internal loading valve to achieve
a completely new control configuration for application
optimization. Current technology is limited to only a single
sensitivity adjustment that affects both internal loading
valves.
The VPC 20 may also be configured as a proportional device with a
mechanical feedback to achieve a "diaphragm type" valve positioner
39, as shown in FIG. 11. Current technology incorporates a
mechanical feedback that directly couples the diaphragm module with
the power module in a linear arrangement. A diaphragm type valve
positioner 39 incorporates a mechanical feedback that separates the
diaphragm module and the power module. The design incorporates
pivoted beam component to couple the power module 22 and the
diaphragm module 39, also shown in FIG. 11.
The base VPC 20 provides Integral function (I) and Derivative
function (D) adjustments. More demanding control applications may
require addition of a Proportional function (P) adjustment in a
"PID" type controller. The present system 10 utilizes a continuous
type Proportional function (P) adjustment that incorporates a
pivoted beam with an adjustable fulcrum. Existing technology does
not have a continuous Proportional function (P) adjustment, but
utilizes a selection of interchangeable components to achieve only
discrete Proportional function (P) values.
Optionally, with reference to FIG. 13-13d, the system 10 may
include a valve manual override (VMO) 46, which is a six-way,
five-position valve utilized in conjunction with the VPC 20. The
VMO 46 provides an ability to override any of the system
configurations and manually operate the process control valve 14 to
which the VPC 20 is coupled. In contrast, current technology is
installed via threaded plumbing connections and multiple pneumatic
tubing lines. The current system 10 allows the VMO 46 to be
installed as an integral component with the VPC 20 utilizing the
unique manifold 23, thereby minimizing the need for any external
plumbing connections and simplifying the design. Additionally, the
manifolds 23 of the system 10 allow for installation and removal of
the VMO 46 without removal of any threaded plumbing fittings.
Rotary type VMO and linear ported type VMO may be used. In the case
of the rotary type VMO, the device is used to interrupt and allow
manual control of the pneumatic output of the pilot by manually
rotating ports. The linear ported type VMO also interrupts and
allows manual control of the pneumatic output of the pilot, but
does so by shifting of a linear ported valve system.
Other key alternate components and embodiments of the system 10 and
VPC 20 are set forth in the paragraphs below.
As previously mentioned, the VPC 20 can use two different internal
valves fluidly coupled to the actuator 32. Known existing designs
have always used the same internal valves in order to achieve a
control function. Comparatively, the loading valves of the present
system 10 can be either normally-open type loading valves or
normally-closed type loading valves. For example, the VPC 20 can be
constructed using one normally-open type loading valve and one
normally-closed type loading valve. Additional adjustments would be
needed in order to tune each loading valve individually, but those
skilled in the art would understand how to make such adjustments.
Such a configuration can be used, for example, where a volume
booster 33 (FIG. 12) is needed in one direction but not is the
opposite direction.
As those skilled in the art will appreciate, existing pneumatic
controllers are available in two configurations: Bourdon tube plus
relay and direct diaphragm. The Bourdon tube plus relay is
available with all variable P I+D functions. The direct diaphragm
controller is only available with variable I+D and selectable P
functions. However, the VPC 20 can also be built on the diaphragm
principal with all P+I+D functions available as variable.
With respect to the use of a pneumatic positioner 35, existing
devices are available as one of either a relay type, spool valve
type or diaphragm type positioner. The relay positioner and spool
valve positioner are both available with rotary or linear feedback.
However, the diaphragm positioner is currently only available with
a linear feedback. The present system 10 provides a diaphragm
positioner with rotary feedback or linear feedback. The rotary
feedback will have a feedback beam driven by the sensing diaphragm
and counterbalanced by the power diaphragms and range extension
spring.
Other possible design alterations include the following: A.
Combining I and D orifice in one manifold; B. Using a smaller
volume tank; C. Using ID controller as the first stage cut
controller over PI and over PID; D. Use of 0.001'' hard coat
anodizing to create a barrier between aluminum and SS screws, which
eliminates electrolysis effect and aluminum corrosion; E. 5.225 and
1500 sensing chambers built as independent chambers versus existing
technology design; and F. Six common springs for all design versus
several cartridges for existing technology.
The matter set forth in the foregoing description and accompanying
drawings is offered by way of illustration only and not as a
limitation. While particular embodiments have been shown and
described, it will be apparent to those skilled in the art that
changes and modifications may be made without departing from the
broader aspects of applicants' contribution. The actual scope of
the protection sought is intended to be defined in the following
claims when viewed in their proper perspective based on the prior
art.
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