The ExxonMobil Research and engineering group tested the self-diagnostic capabilities of pressure transmitters with FOUNDATION fieldbus (FF) capability installed on a refinery FCC unit. This project involved conductin...
详细信息
The ExxonMobil Research and engineering group tested the self-diagnostic capabilities of pressure transmitters with FOUNDATION fieldbus (FF) capability installed on a refinery FCC unit. This project involved conducting a series of tests on the ability of the devices to diagnose plugged impulse lines. Three types of problems associated with the pressure transmitters and purge systems on an FCC unit, and with the FCC process itself, can be detected with the diagnostic capabilities of fieldbus pressure transmitters. In addition to identifying process-related problems, the diagnostics capabilities of fieldbus pressure transmitters should be able to identify conditions related to plugged impulse lines before they cause operational upsets.
Waste heat recovery boilers as applied in refuse waste incinerators are susceptible to fouling. On the tube bundles in the boiler deposits are observed ranging from thin and powdery to thick and sintered with large ri...
详细信息
ISBN:
(纸本)9036514665
Waste heat recovery boilers as applied in refuse waste incinerators are susceptible to fouling. On the tube bundles in the boiler deposits are observed ranging from thin and powdery to thick and sintered with large ridges at the upstream side of the tubes. Both types of layers result in a decrease of the overall heat transfer coefficient of about 27%. To optimize the geometry of the bundle such that the formation of layers is minimized a model is developed that, as a function of the geometry, predicts the local deposition rate of particles. The model incorporates both the transport and the sticking of these particles to the surface. The applied sticking model is based on the two-body approach. The validity of this approach is shown using well-defined experiments in which the rebound characteristics of particles impacting on a powdery deposit are measured. Using the results from the impact experiments the deposition rate is calculated for a tube bank geometry with a varying pitch. The calculated deposition rates, when using the sticking model, are in the same order as the deposition rates reported for the industrial case. From these first calculations, it also appears that the pitch has a strong influence on the formation of a deposit on the tubes.
The basic techniques of cascade and feedforward control are described together with the types of process problem to which they are suited. Their use is illustrated with simple examples. Among these are three-element l...
详细信息
The basic techniques of cascade and feedforward control are described together with the types of process problem to which they are suited. Their use is illustrated with simple examples. Among these are three-element level control, heat exchanger control and distillation control. The latter example quotes the magnitude of the benefits which can be achieved in practice. Other areas where traditional techniques can be used are given. Amongst these are override controls with an illustration from distillation control, 'valve position control' with an example from a fired heater system and the use of calculated variables demonstrated by heat input control.
The paper summarises some of the current problems facing the development and deployment of agent based technology. It introduces some of the different forms that this technology can appear in, and how agent based soft...
The paper summarises some of the current problems facing the development and deployment of agent based technology. It introduces some of the different forms that this technology can appear in, and how agent based software might usefully be deployed in an industrial/commercial environment. Many of the ideas stem from involvement in the DTI sponsored ADEPT development project as part of the ISIP programme.
The International Space Station is ensured a long operational lifetime in low Earth orbit in part by having contaminant deposition rate requirements placed on sensitive external surfaces. To meet the requirements, ext...
详细信息
A general approach to plasma shape control and its application to the Alcator C-Mod tokamak are described. The method is linear in the magnetic measurements but is entirely algorithmic, requiring no fitting of databas...
详细信息
A general approach to plasma shape control and its application to the Alcator C-Mod tokamak are described. The method is linear in the magnetic measurements but is entirely algorithmic, requiring no fitting of databases. Estimators of the shape parameters are based on a complete vacuum reconstruction of the flux, so that control points can be defined anywhere within the reconstructed region. The conversion of flux differences into flux-surface distances and the calculation of appropriate coil currents for controlling each parameter require a specific reference equilibrium. However the control is very insensitive to the choice of reference equilibrium provided that the shape parameters are chosen appropriately. Control current combinations that are orthogonal, in the sense of changing one parameter and not the others, are obtained. Experiments with these estimators and controllers show them to be accurate and robust over a wide range of plasma shapes.
The time is right to transition telerobotics beyond the traditional hazardous environment domain into industrial repair and remanufacturing applications. Air Force depots are prime examples of an industrial environmen...
详细信息
The time is right to transition telerobotics beyond the traditional hazardous environment domain into industrial repair and remanufacturing applications. Air Force depots are prime examples of an industrial environment where small batch sizes, feature uncertainty, and varying workload conspire to make classical industrial robotic solutions impractical and telerobotics a key enabling technology. The United States Air Force, Air Force Material Command, Robotics and Automation Center of Excellence (RACE) has launched the Unified Telerobotics Architecture Project (UTAP) to champion the development of the support infrastructure necessary to foster creative development and innovative utilization of emerging telerobotic technologies for depot applications. The UTAP program is the focus of this paper.< >
The Air Force Material Command Advanced Robotics technology Insertion Program (ARTIP) was formally initiated in August 1992. The ARTIP Program Action Directive (PAD) codifies the mission and responsibilities that the ...
详细信息
The Air Force Material Command Advanced Robotics technology Insertion Program (ARTIP) was formally initiated in August 1992. The ARTIP Program Action Directive (PAD) codifies the mission and responsibilities that the AFMC Robotics and Automation Center of Excellence (RACE) has been actively pursuing since October 1991. AFMC RACE is a command wide focal point, an organic source of expertise to assist the logistic and product centers in improving process productivity through the judicious insertion of robotics and automation technologies. This paper provides an overview of the ARTIP PAD and an update on major RACE activities in support of those objectives.< >
Air Logistic Centers trail the commercial sector in insertion of robotics and automation technologies. Small batch sizes, feature uncertainty, and varying workload have conspired to make classical industrial robotic s...
详细信息
Air Logistic Centers trail the commercial sector in insertion of robotics and automation technologies. Small batch sizes, feature uncertainty, and varying workload have conspired to make classical industrial robotic solutions impractical for a wide range of depot remanufacturing processes. The solution is telerobotics. The challenge is how to judiciously exploit telerobotics to enhance depot industrial processes. In response to that challenge, the AFMC Robotics and Automation Center of Excellence (RACE) has launched a technical initiative to foster creative development and innovative utilization of emerging telerobotic technologies. The goals, plan of attack, and status of that initiative are presented.< >
暂无评论