Other

American Filtrona Corporation

Samsung Electronics Co., Ltd.

Rajan A Jaisinghani

Clyde W Hawley

Thomas A Hamade

Tim G Christensen

Robert A Fjeld

A refrigeration based air handling system design process for significant energy and cost savings in cleanroom and other applications requiring large air change rates is presented. The process utilizes a by pass around the air conditioning system, the ratio of bypass to air conditioning flow being such that minimal or no reheat of the air is required for applications having relative humidity (RH) control requirements and with RH control being achieved via cooling. If dehumidification is achieved by adsorptive processes, then the by pass ratio is varied so as to minimize cooling of the heated dry air. In other non relative humidity control applications the bypass is varied to minimize the air conditioning flow, thereby decreasing cost, but by using optimum cooling coil velocities in a manner such that system energy for airflow is minimized. The energy and cost savings achieved by this process vary between 65% to 15% depending on the Class of the cleanroom and/or on the number of air changes per hour required.

Energy efficient air handling system for cleanrooms

A method and apparatus using deep pleated filters to provide efficient and safe electrically enhanced filtering (EEF), with ultra low pressure drop, higher efficiency of particulate removal and higher dirt holding capacity over the life of the filter. An EEF may be constructed with a housing, with or without an internal air moving device such as a fan, a deeply pleated filter, preferably a V-pack filter with sets of downstream ground electrodes and charge transfer electrodes borne by the exterior surface of the filter packs that form the filtering element. An ionizer assembly that ionizes the gas and charges particles entering the deeply pleated filter and also transfers a charge to the charge transfer electrodes on the filter pack. A plate seals the gasket on the filtering element against the ionizing assembly. A high electrical potential is applied to charging elements in the ionizer and, in some embodiments, a fan or motor assembly. The charge transfer electrodes enable the device to function with a high particle collection field between the charge transfer electrodes and the downstream grounded electrodes to safely and efficiently attain higher entrapment of the particles on the filter medium.

Low pressure drop deep electrically enhanced filter

An improved wire corona charging apparatus and processes for treating webs and films, to improve surface wettability characteristics and other surface properties, and to create permanently charged electrets. Corona produced by wires results in more evenly distributed ion flux under a high level of control, than possible with commonly used bar chargers. Wire chargers are not used in applications that involve webs and films of large width, since at these widths wires can slacken and break, resulting in possible electric shorting that can be a safety hazard in most non-batch processes. The embodiments disclosed overcome these reliability and safety issues.

Wire corona charging apparatus

A capillary pressure measuring device comprises a highly regulated low pressure control system with a vacuum producing subsystem, a sample holder, a vertical positioning mechanism and a weighing device used for measuring the advancing and receding capillary pressure distributions of porous materials using a wetting fluid. Advancing capillary pressure distribution of the porous materials are measured by the steps of applying a highly controlled pressure to a test sample which is in contact with the wetting fluid, so as to allow no or only limited absorption of the fluid in the sample; incrementally reducing the applied pressure and recording the stable or equilibrium fluid weight adsorbed at each increment of the reduced pressure; and calculating the advancing average sample cross section area based capillary pressure distribution and the pore size distribution using the weight absorbed versus applied pressure data. Receding capillary pressure distribution of the porous materials are measured by the steps of saturating the test sample with the wetting fluid; incrementally increasing the applied pressure and recording the release of the absorbed fluid from the test sample; and calculating the receding capillary pressure distribution and the receding average sample cross section area based pore size distribution based on the similar weight versus applied pressure data.

Apparatus and method for measuring the capillary pressure distribution

An electrostatically stimulated air filter and process, contemplates a housing having an fluid intake and a fluid exhaust; a upstream electrode, disposed downstream of the fluid intake, for carrying a ground potential; a filter, disposed downstream of the prefilter, for filtering out contaminants in the fluid; an ionizing electrode, disposed between the filter and the prefilter, for carrying a second potential; and a downstream electrode, disposed downstream of the filter, for carrying a ground potential; and a fan, downstream of the filter, for driving air through the prefilter and the filter. Ionization of incoming fluid occurs as a result of electric fields generated by the downstream electrode, the ionizing electrode, and the upstream electrode. The filter comprises an upstream dielectric layer and a downstream conductive layer, usually fibers coated with activated carbon powder.

Safe ionizing field electrically enhanced filter and process for safely

An electrically stimuated filter assembly includes a filter unit in which an air gap is maintained between the filter medium and electrodes disposed on opposite sides of that medium, thereby preventing degradation of filter efficiency by humid filtered fluid. The filter medium is a sheet-like member folded in multiple accordion pleats and disposed between two plate electrodes, one of which is grounded to the chassis, the other of which is at high voltage. The air gaps are established by insulative plastic combs having bases secured to the electrode plates and teeth projecting from the bases into troughs of the folded filter. The high voltage plate is on the downstream side of the filter and mounted recessed from the downstream opening by insulative tubes secured to both the filter housing and the high voltage plate. A precharger is disposed in the assembly upstream of the filter unit and includes plural individual high voltage wires suspended in mutually spaced parallel relation across the flow path. The precharger is housed in a grounded metal frame which is insulated from the wires.

Electrically stimulated filter method and apparatus

A method and apparatus for removing particulate matter suspended in low conductivity liquids employs extrinsic ions to electrically charge suspended particles. A unipolar current of the extrinsic ions is passed through the flowing liquid to efficiently charge the particles. The charged particles may then be removed by agglomeration and sedimentation techniques, or by other means. A stripping section is disposed upstream of the region in which the particles are charged, in order to strip the double layer of counter ions from the particles before the particles are charged.

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Midlothian, VA, United States of America

Rajan A Jaisinghani