A specific blackboard expert system to simulate and automate the design of high recirculation airlift reactors

Journal of Environmental Engineering and Science

2017

Highlights: Fast and efficient methods are presented for designing High-Recirculation Airlift-Reactors.  Two-phase flow of water and air is modelled.  Improvements are made by refining steady-state models of fluid dynamics.  Solutions are produced by varying superficial gas velocity.  Solutions are produced by simultaneously varying down-comer and riser diameters.ABSTRACT: High-Recirculation Airlift-Reactors (HRARs) are efficient. They use air to push a mixture around the reactor and to provide oxygen for biological micro-organisms. HRARs have been designed using programs created in the 1970s by ICI. They are limited in functionality and accuracy and need significant expert interpretation. This paper describes the creation of new structured methods that are faster and more efficient and replace the ICI methods. Models used for the calculations and the way in which they were implemented are described. The paper then describes improvements to design by analysing and improving the steady-state models of fluid dynamics within a HRAR. The models also delivered information about reactor design, especially which parameters to modify to reach a steady state result. Two-phase flow of water and air is modelled and applied to HRARs. Tests evaluated the models and some results are included. They show that varying superficial gas velocity or simultaneously varying down comer and riser diameters can create a steady-state solution. Mathematical models are used to forecast steady-state situations in the HRAR for specific gas or liquid flow rates and for various constructions. Experimental relationships forecast mass transfers between gas and liquid phases and they predict flow.

Section: Figure 1 Here a High-recirculation Airlift-reactormentioning

confidence: 99%

Section: Stabilitymentioning

confidence: 99%

Section: Stabilitymentioning

confidence: 99%

Section: Stabilitymentioning

confidence: 99%

See 2 more Smart Citations

New method to design large-scale high-recirculation airlift reactors

Journal of Environmental Engineering and Science

2017

“…1,3,5,8,[11][12][13] Systems have tended to be open loop. Intelligent systems [40][41][42][43][44] required sensors, 45,46 and control algorithms 47-50 that could process information from a tele-operator and sensors and use this information to assist the tele-operator. Common disturbances include differences in mobile-robot wheels or tractors or their different reaction to surfaces and/or gradients.…”

Section: Introductionmentioning

confidence: 99%

Analysis of successes and failures with a tele-operated mobile robot in various modes of operation

Stott²,

Robinson

et al. 2011

Robotica

The effect on failure rates of the way tele-operators interact with mobile robots is investigated. Human tele-operators attempted to move a robot through progressively more complicated environments with reducing gaps, as quickly as possible. Tele-operators used a joystick and either watched robots, while operating them, or used a computer screen to view scenes remotely. Cameras were either mounted on the robot to view the space ahead of the robot or mounted remotely so that they viewed both the environment and robot. Tele-operators completed tests both with and without sensors. Both an umbilical cable and a radio link were used.

Improving Human-Machine Interaction for a Powered Wheelchair Driver by Using Variable-Switches and Sensors that Reduce Wheelchair-Veer

Advances in Intelligent Systems and Computing

Langner²,

Bausch

et al. 2019

The integration of proportional switches for human-computer interaction and sensors with veer correction systems are presented. The transducers and sensors improve control, assist wheelchair drivers and reduced wheelchair veer, especially on slopes. The systems also reduce effort. The proportional switches are particularly useful for disabled people who do not have enough skill to use a joystick, or who lack sufficient hand-grasp and release ability, or who have movement disorders. The new systems were tested using laboratory test rigs. The test rigs were reused later to teach human users. A rolling road was then built to test the systems before user trials were undertaken. The angle of the wheelchair casters provided feedback and that feedback was used to reduce drift. A new electronic system matched the caster angles to the driver input. A case study is described. Results are presented, and they suggest there are advantages to using variable rather than digital or binary switches. The veer correction system can assist when a user is traversing a slope. The transducers and systems have been tested at Chailey heritage and proved to be useful in assisting poweredwheelchair users. The proportional switches isolate the gross motor functions and filter out uncontrolled movement. The sensor system helps users to steer on uneven or sloping ground. The transducers also provide more control during turning and can reduce the turn radius as well as lowering frustration and conserving energy.