The Babcock & Wilcox Company

Elsag International B.v.

Other

Marion A Keyes, Iv

Azmi Kaya

William L Thompson

Ralph K Johnson

Jeffrey A Beller

Roger Kammerer

Jeremiah J Shaffer

Donald J Dziubakowski

William H Moss

Michael P Lukas

Thomas J Scheib

Suresh C Agarwal

Robert E Pocock

Michael S Willey

Edward D Janecek

James D Schoeffler

Joseph M Giachino

Theodore N Matsko

Donald K Frerichs

James K Knudsen

Peter K Lui

Jack W Malcolm

Richard A Salmen, Deceased

Jack W Malcolm, Deceased

Dan E Forney

Andre T Abromaitis

A neural network control based on a general multi-variable nonlinear dynamic model incorporating time delays is disclosed. The inverse dynamics of the process being controlled is learned represented by a multi-layer neural network which is used as a feedforward control to achieve a specified closed loop response under varying conditions. The weights between the layers in the neural network are adjusted during the learning process. The learning process is based on minimizing the combined error between the desired process value and the actual process output and the error between the desired process value and the inverse process neural network output.

Method and procedure for neural control of dynamic processes

A method and apparatus for controlling the delignification process by monitoring and minimizing variations in the Kappa Number and the digester residual chemical concentration. A parameter representative of the H factor for the delignification process and a measurement of the initial chemical concentration are utilized to produce signals representative of the actual Kappa Number and the residual acid concentration in the digester. The expected perturbations in Kappa Number and the residual chemical concentration are compared with target values for same to produce estimated errors due to mismatch which are compared with actual measured errors for these parameters to produce compensated control errors for same. The compensated control errors are utilized to modify the target values for the H factor and the initial chemical concentration by modifying the chemical charge and the time versus temperature operating parameters of the digestings to regulate pulp Kappa number and spent cooking liquor residual chemical concentrations of the process.

Method of modeling and control for delignification of pulping

A method and apparatus for controlling the delignification process by monitoring and minimizing variations in the Kappa Number and the digester residual chemical concentration. A parameter representative of the H factor for the delignification process and a measurement of the initial chemical concentration are utilized ot produce signals representative of the actual Kappa Number and the residual acid concentration in the digerter. The expected perturbations in Kappa Number and the residual chemical concentration are compared with target values for same to produce estimated errors due to mismatch which are compared with actual measured errors for these parameters to produce compensated control errors for same. The compensated control errors are utilized to modify the target values for the H factor and the initial chemical concentation by modifiying the chemical charge and the time versus temperature operating parameters of the digestings to regulate pulp Kappa number and spent cooking liquor residual chemical concentrations of the process.

System for modeling and control for delignification of pulping

An on-line system that measures the strength of material within a web without contacting same is disclosed. Two laser sources having beams which impinge upon the web of material are positioned so that their respective beams are spaced a predetermined distance apart. The first laser source induces a radially propagating ultrasonic wave within the material. The ultrasonic wave causes the beam from the second laser source to be reflected and intercepted by a light sensor permitting the velocity of the wave and the strength of the material to be determined.

Non-contacting on-line paper strength measuring system

A method and apparatus for controlling the delignification process by monitoring and minimizing variations in the Kappa Number and the digester residual chemical concentration. A parameter representative of the H factor for the delignification process and a measurement of the initial chemical concentration are utilized to produce signals representative of the actual Kappa Number and the residual acid concentration in the digester. The expected perturbations in Kappa Number and the residue chemical concentration are compared with target values for same to produce estimated errors due to mismatch which are compared with actual measured errors for these parameters to produce compensated control errors for same. The compensated control errors are utilized to modify the target values for the H factor and the initial chemical concentration by modifying the chemical charge and the time versus temperature operating parameters of the digestings to regulate pulp Kappa number and spent cooking liquor residual chemical concentrations of the process.

Apparatus for controlling the degree of cooking in a digester

Method for controlling the degree of cooking in a digester

A surge control system (16) is provided for a compressor (14) which anticipates the actual surge condition and initiates anti-surge protection in proportion to the magnitude of the anticipated surge condition. This is done by providing a feed forward signal (20) to a summing station (48) along with a normally generated surge control line point (44) to offset this point (44) by an amount determined by the feed forward signal (20). This offset point (50) is used as an input to a controller for controlling the bypass valve (28) in a bypass loop (30) around the compressor (14).

Compressor surge control method

A surge control system (16) is provided for a compressor (14) which anticipates the actual surge condition and initiates anti-surge protection in proportion to the magnitude of the anticipated surge condition. This is done by providing a feed foward signal (20) to a summing station (48) along with a normally generated surge control line point (44) to offset this point (44) by an amount determined by the feed forward signal (20). This offset point (50) is used as an input to a controller for controlling the bypass valve (28) in a bypass loop (30) around the compressor (14).

Compressor surge control system

A technique for producing a three-dimensional holographic display which is updatable in real time is disclosed. A spinning lens device intercepts a two-dimensional display on a projection television receiver and transforms same into a three-dimensional holographic display in free space. The holographic display is modifiable by the control room operator and process control variables can be readily superimposed thereon.

Holographic operator display for control systems

A carbon monoxide detector comprises a single monochromatic infrared source which is arranged to alternately direct light through two separate gas-containing test chambers. The first chamber is supplied with gas to be tested which has an unknown carbon monoxide content. A catalytic burning chamber is connected between the first and second chambers to receive gas from the first chamber, burn the carbon monoxide in the gas to carbon dioxide and supply the carbon monoxide free gas to the second chamber. A single infrared light detector is provided for receiving light as it comes alternately from the two chambers. The light from the two chambers is compared to determine the amount of carbon monoxide present in the gas of the first test chamber. Since the same background gas is provided in both chambers and only a single infrared source and detector are utilized, inaccuracies due to differences in background detection, infrared source intensity and infrared detector sensitivity are overcome.

Carbon monoxide detector

A display system for displaying select dynamic process data of plant operations to an operator providing a display of only dynamic data having a predetermined difference between current and stored values.

Exception processing of operator displays

A performance monitor generates a fouling factor which indicates the level of fouling of a heat exchanger having a heat exchange surface area and through which a heat exchange medium passes having a known specific heat. Temperature transmitters are utilized to obtain values for the input and output temperatures of the heat exchange medium as well as the temperature in the heat exchanger of a heat exchange fluid used to transfer heat to or from the heat exchange medium. Modules are used to generate a value for an actual heat transfer coefficient in the heat exchanger as a function of the temperatures, flow rate and constant parameters such as area and specific heat, for the heat exchanger. The actual heat transfer coefficient is compared with a nominal or original heat transfer coefficient to determine if any deterioration in the coefficients has occurred which reflects the fouling of the heat exchanger. A simple ratio of the nominal to actual heat transfer coefficient is taken as a measure of this fouling factor.

Heat exchanger performance monitor

A system for processing and selectively transmitting process signals to a computer and/or a display device is disclosed. The system utilizes a binary full adder (38) to add the incoming signal, in inverted form, to the previously transmitted signal to obtain the difference therebetween. A binary comparator (52) compares the difference with a predetermined value, established by thumbwheel switches (46), and if the difference exceeds the predetermined level, causes the actuation of a flip-flop (54) and a bistable latch (32) permitting the incoming signal to be transmitted to a computer and/or a display device.

System for direct comparison and selective transmission of a plurality

An adaptive gain surge control system (18) is disclosed for a centrifugal compressor (14) which reacts to both normal and emergency surge conditions by controlling a bypass valve (48) across the compressor (14) inlet and outlet in response to a variable gain (G) determined by the offset (d) of the surge control line from the surge line of the compressor.

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Chagrin Falls, OH, United States of America

Marion A Keyes, Iv