초록 ▼

The system for controlling flow characteristics allows a user to selectively modify the inherent fluid flow characteristics of a fluid transmission system including a flow process controller and a control valve positioner. The system includes a programmable flow controller having an input adapted fo

The system for controlling flow characteristics allows a user to selectively modify the inherent fluid flow characteristics of a fluid transmission system including a flow process controller and a control valve positioner. The system includes a programmable flow controller having an input adapted for receiving an input signal from the flow process controller. The programmable flow controller selectively modifies the input signals generated by the flow process controller depending upon user-selectable flow parameters. An output is in communication with the programmable flow controller, with the output being adapted for transmitting output signals to the control valve positioner (and the valve connected thereto). A user interface is provided for inputting the user-selectable flow parameters to the programmable flow controller for modification of the input signal to the user-selectable flow parameters.

대표청구항 ▼

We claim: 1. A method for controlling fluid flow characteristics, comprising the steps of: providing a programmable flow controller; positioning the programmable flow controller between a flow process controller and a control valve positioner; programming desired user-selectable flow characteristic

We claim: 1. A method for controlling fluid flow characteristics, comprising the steps of: providing a programmable flow controller; positioning the programmable flow controller between a flow process controller and a control valve positioner; programming desired user-selectable flow characteristics into the programmable flow controller, the programming of the desired user-selectable flow characteristics including a selected flow curve ƒ(u), wherein ƒ(u) represents a percentage flow rate and u represents a percentage of valve stem position controlled by said control valve positioner; storing the user-selectable flow characteristics in computer memory; inputting a set of inherent valve parameters into the programmable flow controller; calculating a set of desired valve parameters from the user-selectable flow characteristics; comparing the set of inherent valve parameters to the set of desired valve parameters to determine a difference; calculating a correction factor according to the difference between the set of inherent valve parameters and the set of desired valve parameters; correcting a control signal from the flow process controller according to the correction factor to form a modified control signal; and transmitting the modified control signal to the control valve positioner. 2. The method for controlling fluid flow characteristics as recited in claim 1, wherein said step of programming the desired user-selectable flow characteristics includes manually entering the desired user-selectable flow characteristics into the programmable flow controller. 3. The method for controlling fluid flow characteristics as recited in claim 1, wherein said step of programming the desired user-selectable flow characteristics includes importing a table of previously stored desired user-selectable flow characteristics into the programmable flow controller. 4. The method for controlling fluid flow characteristics as recited in claim 1, further comprising the step of inputting a set of desired valve characteristics, wherein the step of calculating the set of desired valve parameters is based upon the user-selectable flow characteristics and is further based upon desired valve characteristics. 5. The method for controlling fluid flow characteristics as recited in claim 4, wherein the step of inputting a set of desired valve characteristics includes manually inputting the set of desired valve characteristics into the programmable flow controller. 6. The method for controlling fluid flow characteristics as recited in claim 4, wherein the step of inputting a set of desired valve characteristics includes importing a previously saved set of desired valve characteristics into the programmable flow controller. 7. The method for controlling fluid flow characteristics as recited in claim 1, wherein said step of programming desired user-selectable flow characteristics into the programmable flow controller includes selection of a desired flow curve ƒ(u) from the group consisting of: a linear curve, a parabolic curve, a hyperbolic curve, a square-root curve, a quick opening curve and an equal percentage curve.