Electrical fluid driving

Generai description. Galvanic corrosion refers to the preferential corrosion of the more reactive member of a two-metal pair when the metals are in electrical contact in the presence of a conductive fluid (see Chap. 16, Galvanic Corrosion ). The corrosion potential difference, the magnitude of which depends on the metal-pair combination and the nature of the fluid, drives a corrosion reaction that simultaneously causes the less-noble pair member to corrode and the more-noble pair member to become even more noble. The galvanic series for various metals in sea water is shown in Chap. 16, Table 16.1. Galvanic potentials may vary with temperature, time, flow velocity, and composition of the fluid. 

Reactor 7 [R 7] Electrical Interconnect for Fluid Driving - Chip-to-world... 

Similar to computer technologies, so-called plug and play micro fluidic devices were developed. These devices are composed of a fluid driving unit and a polymer chip containing micro fluidic channels and reservoirs. The one and only connection is an electrical bus system which connects the chip with the external control unit. By filling the reservoirs with reagents, the chip can be used for performing chemical reactions or biochemical analysis [72],... 

A car using a central electric motor activating a fluid drive to turbines on all wheels was designed, built, and operated by the engineers in the physical science workshop at Flinders University, Ade laide, Australia, in 1976. 

Compressor drives. Compressors and blowers in fluid cracking units may be either steam or electrically driven (209). Steam turbines were preferred over electric-motor drives in the design of early units, partly because of fear of a power failure. However, under some circumstances, the economics favor the use of electric motors. Several units have been built with electrically driven main air blowers, and at least one refiner has selected electric motors for the air blower, gas compressor,... 

Figure 5-10 Detection system for LIF detection on microchips. Fluidic and electrical interfaces are indirectly fundamental to the detection system.The fluidic interface drives the preparation and flushing of the chip preseparation and postseparation, while the electrical interface drives the electrophoretic separation and controls the flow of fluid through the chip architecture via electrokinetic valving.

A long memoir by Volta in two parts summarises his lecture to the Institut, repeats the above statements, and reports that by measuring the electrometer deflections with different pairs of metals he found that the forces which drive the electric fluid (alia forza. .. quelle spinge il fluido elettrico) from the first metal to the second are silver/copper i, copper/iron 2, iron/tin 3, lead/tin i, lead/zinc 5. Then the force for silver/zinc in immediate contact is 12 ( = i+ 2 + 3 + i+5), copper/tin 5 ( = 3 + 2), iron/zinc 9 (= 5 +1 + 3), etc. Thus the force or impulsion with which two metals act on the electric fluid is equal to the sum of the forces of the series of metals which stand between them, and... the electric force is the same as that which arises when the two extreme metals are in direct contact. Metals of any kind interposed between the two extreme metals have no effect on the force of the latter. This is the first statement of what Maxwell called Volta s law of contact electricity . Volta showed that it did not hold if humid conductors were in the circuit. E.g. HgO/Zn = I, hence if the law held HgO/Ag should be 13, but it was only i ( 25). The humid conductor reduces the electromotive force between the metals so that it is not balanced at the metallic junction, and a continuous current is kept up ( 7). In a summary of his publications Volta repeats his view that the current arises from the contact of two different conductors, above all metallic , and that the chemical action in the pile is not concerned with the production of electricity. 

The electrical and electronic control system consists of the field devices feedback system, electric motor drive system and the safety and manual logic system. The commands from the micros ar checked in the safety logic system for safe operation before being sent to the fluid power system. The fluid power system operates the device in the correct direction, at the required speed and force, to position it accurately. The feedback device (say potentiometer) is read by the micro and appropriate commands initiated. The device is also connected to the computer independent display on the console. Operation and alarm messages are diplayed on the VDU and logged by the printer. 

Pneumatic systems use the wave motion to pressurize air in an oscillating water column (OWC). The pressurized air is then passed through an air turbine to generate electricity. In hydrauhc systems, wave motion is used to pressurize water or other fluids, which are subsequendy passed through a turbine or motor that drives a generator. Hydropower systems concentrate wave peaks and store the water dehvered in the waves in an elevated basin. The potential energy suppHed mns a low head hydro plant with seawater. 

Power, Energy, and Drives. Centrifuges accomplish their function by subjecting fluids and soHds to centrifugal fields produced by rotation. Electric motors are the drive device most frequently used however, hydrauHc motors, internal combustion engines, and steam or air turbines are also used. One power equation appHes to all types of centrifuges and drive devices. 

Electromagnetic Force When the fluid is an electrical conductor, as is the case with molten metals, it is possible to impress an electromagnetic field around the fluid conduit in such a way that a driving force that will cause flow is created. Such pumps have been developed for the handling of heat-transfer hquids, especially for nuclear reactors. 

It is important first to distinguish between a closed cyclic power plant (or heat engine) and an open circuit power plant. In the former, fluid passes continuously round a closed circuit, through a thermodynamic cycle in which heat ((2b) is received from a source at a high temperature, heat (Qa) >s rejected to a sink at low temperature and work output (IT) is delivered, usually to drive an electric generator. 

Mud pumps consist of a power input end and a fluid output end. The power input end, shown in Figure 4-101, transfers power from the driving engine (usually diesel or electric) to the pump crankshaft. The fluid end does the actual work of pumping the fluid. A cross-section of the fluid end is shown in Figure 4-102. 

Enhanced oil-recovery processes include chemical and gas floods, steam, combustion, and electric heating. Gas floods, including immiscible and miscible processes, are usually defined by injected fluids (carbon dioxide, flue gas, nitrogen, or hydrocarbon). Steam projects involve cyclic steam (huff and puff) or steam drive. Combustion technologies can be subdivided into those that autoignite and those that require a heat source at injectors [521]. 

The contribution of transport under the influence of the electric field (migration), which, if appreciable, should be subtracted from the total mass flux. The use of excess inert (supporting) electrolyte is recommended to suppress migration effects. However, it should be remembered that this changes the composition of the electrolyte solution at the electrode surface. This is particularly critical in the interpretation of free-convection results, where the interfacial concentration of the inert as well as the reacting ions determines the driving force for fluid motion. 

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