Modular Fluid System

The Modular Fluid System (MFS) concept as base system for the realization of Micro-TAS, as well as a number of different micromechanical components for use in Micro-TAS are presented. The correspondence of MFS to electronic breadboards is discussed, and an example of a possible "mixed" fluidic/electronic board is given. The consequences of downscaling for the operation of sensors in Micro-TAS are discussed, and a number of components, sensors, sieves, mixers, valves and pumps are presented. Finally, the importance of the development of design tools and rules, especially bondgraph modelling, for MFS is emphasized. 

In this contribution we introduce the Modular Fluid System concept [1] as a generic Micro-TAS breadboard, comparable and additional to its electronic counterpart. We will treat the components or fimetions, necessary to build such a system. Systems may greatly differ in their specifications. This means that components must be available in a range to meet these specifications. Hopefully a set of components can be designed to meet this range, while on the other hand they fit into a system with standard interconnection rules. 

Theo S J Lammennk, Albert van den Berg and Jan H J Fluitman, Brochure MESA-Modular Fluid Systems, available on request... 

In addition to valves, pumps, nozzles and dispensers, microtechnologies make available other modular fluid-flow components such as flow sensors, micromixers and reaction chambers. Customized fluid systems can now be produced solely on the basis of these modular components. Typical applications are microanalysis systems and microdosing systems, for example for dosing medications, chemical reagents, lubricants and adhesives. 

Use of boric acid and glycerol in modular drilling fluid system benefits include improved lubrication, reduced mud viscosity, reduced bit balling, reduced cohesion of drilled rock (easier drilling)— attributed to the adsorption on edges of clay particles of a surface active borate ester formed between boric acid and glycerol. 

The first use of supercritical fluid extraction (SFE) as an extraction technique was reported by Zosel [379]. Since then there have been many reports on the use of SFE to extract PCBs, phenols, PAHs, and other organic compounds from particulate matter, soils and sediments [362, 363, 380-389]. The attraction of SFE as an extraction technique is directly related to the unique properties of the supercritical fluid [390]. Supercritical fluids, which have been used, have low viscosities, high diffusion coefficients, and low flammabilities, which are all clearly superior to the organic solvents normally used. Carbon dioxide (C02, [362,363]) is the most common supercritical fluid used for SFE, since it is inexpensive and has a low critical temperature (31.3 °C) and pressure (72.2 bar). Other less commonly used fluids include nitrous oxide (N20), ammonia, fluoro-form, methane, pentane, methanol, ethanol, sulfur hexafluoride (SF6), and dichlorofluoromethane [362, 363, 391]. Most of these fluids are clearly less attractive as solvents in terms of toxicity or as environmentally benign chemicals. Commercial SFE systems are available, but some workers have also made inexpensive modular systems [390]. 

Some of the newer procedures use the same basic principles as the older extraction methods but provide fast and easy-to-use options and generally consume less organic solvent. For the most part, they have higher initial purchase price than the traditional methods. Examples include supercritical fluid extraction, accelerated solvent extraction, and automated solid-phase extraction and microextraction. Modular systems are now readily available that automate these proce-... 

A modular micro structured chemical reaction system (ICS) similar to [R 14] is claimed by Bard [84]. The system can use various replaceable and interchangeable cylindrical or rectangular reactors. Generally, the ICS system can include fluid flow handling and control components, mixers, reaction chip-type units, separator devices, process variable detectors and controllers and a computer interface for communicating with the master control center (see Figure 4.31) [84],... 

Planar modular concept for fluid handling micro-systems with functional modules on top of a Mixed Circuit Board... 

Simulation techniques suitable for the description of phenomena at each length-scale are now relatively well established Monte Carlo (MC) and Molecular Dynamics (MD) methods at the molecular length-scale, various mesoscopic simulation methods such as Dissipative Particle Dynamics (Groot and Warren, 1997), Brownian Dynamics, or Lattice Boltzmann in the colloidal domain, Computational Fluid Dynamics at the continuum length-scale, and sequential-modular or equation-based methods at the unit operation/process-systems level. 

The design of a multi-purpose plant for the continuous extraction of liquids with supercritical fluids is presented. To provide flexibility in order to treat different feedstocks, a modular concept was developed based on experience gained in the operation of bench-scale and pilot plants. Four test systems were chosen in order to determine the proper dimensions for the equipment. Based on experimental data, e.g. measurements of flooding points and maximum flows for various column internals, the design pressure and temperature and heat exchange requirements were determined. The plant was built by a German manufacturer and was operated successfully by a Canadian company in Edmonton, Alberta. 

According to our modular approach, the lattice fluid confined by hard repulsive substrates may be viewed as a bulk system, in which serves to introduce surfaces. We can then express the grand-potential density as... 

R.O. systems utilizing externally wound tubular membrane element in modular assemblies have been used in the desalination of brackish and sea waters, the treatment and/or concentration of industrial waste waters, the separation/concentration of fluid food, pharmaceuticals and chemical solutions, and the manufacture of water purifiers for domestic use. Generally, externally wound tubular membrane systems have been found to be highly suitable for ultrafiltration applications in the processing Industry and in water pollution control applications. 

Establishes properties and physical dimensions that define the interface for surface-mount fluid distribution components with elastomeric sealing devices used within process analyzer and sample-handling systems. The interface controls the dimensions and location of the sealing surfaces to allow change of just one element of the system without modification of the entire system, making the system modular from both a design and a maintenance standpoint. 

ANSI/ISA SP76.00.02-2002 Modular Component Interfaces for Surface-Mount Fluid Distribution Components - Parti Elastomeric Seals, Instrumentation, Systems, and Automation Society (ISA), Compositional Analyzers Committee, 2002, www.isa.org. 

Backbone interface based on the bus concept where the flow passes through a central spine has been developed [12]. The modular backbone allows both commercial and demonstration type of microstmctured devices to be coupled in all three dimensions in a flexible and easy manner. Microstmctured heat exchangers, reactors, and mixers made of different manufacturers are surface-mounted on this backbone. The backbone itself consists of elements which can be combined individually and flexibly in all directions, according to the demands of the plant to be built. The backbone provides the flow paths for fluids and electrical conduits for power supply and signal transmission of sensors and actuators as shown in Fig. 5. With this united microreactor system, sulfonation of toluene with gaseous SO3 was successfully conducted to give... 

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