Liquid dielectric

About: Liquid dielectric is a research topic. Over the lifetime, 3702 publications have been published within this topic receiving 45150 citations.

Solid insulation for electrical apparatus

Abstract: An improved thermally stable polymeric insulation for use in electrical apparatus and particularly in transformers operated in the presence of transformer oil is a substitute for the conventional cellulosic pressboard, which improved insulation consists of an isotactic polymeric hydrocarbon resin in at least partially crystalline form and cross-linked, 1,2-butadienes and copolymers having a low dielectric constant substantially matching that of the liquid dielectric and having relatively low swelling characteristics when immersed in hot liquid petroleum oil dielectric over an extended period of time.

Apparatus for removing water from dielectric oil in electrical power transformers

Abstract: An apparatus for removing water from a dielectric oil which includes a vacuum pump (56) which militates against the introduction of air into the dielectric oil and a thin film capacitance sensor (48) for monitoring the amount of moisture present in the dielectric oil.

Wettability Manipulation by Interface-Localized Liquid Dielectrophoresis: Fundamentals and Applications.

Abstract: Electric field-based smart wetting manipulation is one of the extensively used techniques in modern surface science and engineering, especially in microfluidics and optofluidics applications. Liquid dielectrophoresis (LDEP) is a technique involving the manipulation of dielectric liquid motion via the polarization effect using a non-homogeneous electric field. The LDEP technique was mainly dedicated to the actuation of dielectric and aqueous liquids in microfluidics systems. Recently, a new concept called dielectrowetting was demonstrated by which the wettability of a dielectric liquid droplet can be reversibly manipulated via a highly localized LDEP force at the three-phase contact line of the droplet. Although dielectrowetting is principally very different from electrowetting on dielectrics (EWOD), it has the capability to spread a dielectric droplet into a thin liquid film with the application of sufficiently high voltage, overcoming the contact-angle saturation encountered in EWOD. The strength of dielectrowetting depends on the ratio of the penetration depth of the electric field inside the dielectric liquid and the difference between the dielectric constants of the liquid and its ambient medium. Since the introduction of the dielectrowetting technique, significant progress in the field encompassing various real-life applications was demonstrated in recent decades. In this paper, we review and discuss the governing forces and basic principles of LDEP, the mechanism of interface localization of LDEP for dielectrowetting, related phenomenon, and their recent applications, with an outlook on the future research.

RF heating of a dielectric fluid

Abstract: An apparatus for applying electromagnetic energy to a dielectric fluid includes a chamber ( 20 ) to contain the dielectric fluid. A at least three parallel or coaxial electrode plates ( 401 - 409 ) is arranged within the chamber to apply substantially equal electromagnetic energy per unit volume of the dielectric fluid between neighbouring ones of the at least three electrode plates. Electrical conductors ( 416, 426 ) are electrically connected to electrode plates to apply a radio frequency electric field between neighbouring ones of the at least three electrode plates. In a first embodiment the electrode share connected in series and in an alternative embodiment the electrodes are connected in parallel.

Cooling system for foam insulated bus

Abstract: In isolated phase bus systems comprising spaced substantially parallel aligned inner and outer tubular conductors, the interior space thereof being filled with a dielectric foam insulation made up of a predetermined percentage of open cells to enable free migration of vapors. A liquid dielectric having an appropriately selected and relatively low boiling point is inserted into the bus until it reaches a level whereby it substantially covers the inner conductor which is supported by the foam insulation. Conduction of current raises the bus temperature. If the magnitude of the current is such as to raise the temperature above a predetermined level, the liquid dielectric boils and vaporizes. The vaporized dielectric tends to move to a cooler zone within the structure and become condensed whereby the liquid dielectric continuously recirculates through the system to prevent the bus from exceeding a predetermined operating temperature. The controlled amount of the open cells provided in the foam and the positioning of the inner conductor below the longitudinal axis of the outer conductor substantially reduces the amount of liquid dielectric required with no reduction in dielectric withstand. The liquid dielectric may for example be taken from the group comprised of freons, ucons, or other liquids having predetermined relatively low boiling points and having the characteristics that they are non-reactive with the dielectric foam insulation.